Paper - The genesis and development of the nasolacrimal passages in man: Difference between revisions

From Embryology
(Created page with "Schaeffer JP. The genesis and development of the nasolacrimal passages in man. (1912) {{Amer. J Ana...")
 
Line 35: Line 35:


==Introduction==
==Introduction==
A brief review of the literature on the nasolacrimal passages
A brief review of the literature on the nasolacrimal passages [laerimal duets (lachrymal canaliculi), lacrimal sac, nasolacrimal duct] shows that diverse views were from time to time advanced on the genesis and development of these passages Before considering the material studied in this investigation I Want to refer to some of the theories held by earlier Writers. I do not wish to give a complete resume on the history of the development, but rather in a brief manner indicate the evolution in our knowledge concerning the genesis and development of these passages.
[laerimal duets (lachrymal canaliculi), lacrimal sac, nasolacrimal
duct] shows that diverse views were from time to time advanced
on the genesis and development of these passages Before considering the material studied in this investigation I Want to refer
to some of the theories held by earlier Writers. I do not wish to
give a complete resume on the history of the development, but
rather in a brief manner indicate the evolution in our knowledge
concerning the genesis and development of these passages.


v. Baer (’28~’37) thought that the nasolacrimal passages had
v. Baer (’28~’37) thought that the nasolacrimal passages had their origin in a diverticulum from the ‘ Rachenhohle.’ His theoryl presumably was based upon hypothetical conclusions, since it is entirely unsupported.
their origin in a diverticulum from the ‘ Rachenhohle.’ His theoryl
presumably was based upon hypothetical conclusions, since it is
entirely unsupported.


Burdach (’37) in his ‘Die Physiologie als Erfahrungswissenschaft’ Writes briefly concerning the genesis of the nasolacrimal
Burdach (’37) in his ‘Die Physiologie als Erfahrungswissenschaft’ Writes briefly concerning the genesis of the nasolacrimal


1 Die Bildung des Thrzmenkanals (in birds) glaubte ich in einerA11ssti'1lpung
1 Die Bildung des Thrzmenkanals (in birds) glaubte ich in einerA11ssti'1lpung der Rachenhohle, die zuerst nur wenig vor der Eustachischen Rohre liegt und sehr bald nach dieser sichtbar wird, zu erkennen, doch habc ich bisher noch nicht den gesammten Vorgang verfolgt. Uber Entwiclcolungsgeschichte der Thiere, Thiel 2, s. 116. '
der Rachenhohle, die zuerst nur wenig vor der Eustachischen Rohre liegt und
sehr bald nach dieser sichtbar wird, zu erkennen, doch habc ich bisher noch nicht
den gesammten Vorgang verfolgt. Uber Entwiclcolungsgeschichte der Thiere,
Thiel 2, s. 116. '


Der Thranengang stillpt sich auch hier (in mammals) aus der Rachenhijhle
Der Thranengang stillpt sich auch hier (in mammals) aus der Rachenhijhle gegen das Ange hervor und liegt Anfangs hintcr den Muscheln,~die nur, indem sie sich verlangern, sich iiber ihn ziehen. Uber‘Entwickelungsgeschichte der Thiere, Thiel 2, S. 219.
gegen das Ange hervor und liegt Anfangs hintcr den Muscheln,~die nur, indem sie
sich verlangern, sich iiber ihn ziehen. Uber‘Entwickelungsgeschichte der Thiere,
Thiel 2, S. 219.


1
1


ram AMERICAN JOURNAL or ANATOMY, VOL. 13, so. 1
ram AMERICAN JOURNAL or ANATOMY, VOL. 13, so. 1 MARCH, 1912 2 J. PARSONS SCI-IAEFFER
MARCH, 1912
2 J. PARSONS SCI-IAEFFER


passages, but does not state his meaning clearly? He apparently
passages, but does not state his meaning clearly? He apparently thought that the nasolaerimal passages had their origin in a diverticulum or skin-fold (‘Hautfalte’) in the region of the medial palpebral commissure (internal canthus) and, since the nascoptic‘ fissure is obliterated by the eighth week of embryonal life, he must have thought that the ‘Hautfaltc’ grew into the substance of the maxilla, ultimately reaching the nasal cavity. Burdach may have had the right conception of the development of the nasal end of the naselaerimal duct, but in the genesis of the nasolacrimal passages from a skin-fold (‘Hautfalte’) in the region of the medial palpebral commissure he erred (providing the writer interprets his statement correctly). It is difficult to say what Burdach meant by his ‘Hautfalte.’ That the anlage of these passages comes to lie in the body of the maxilla is true, but it comes about in an entirely different Way as Will be seen subsequently. His theory would not explain the origin of the paired lacrimal ducts.
thought that the nasolaerimal passages had their origin in a
diverticulum or skin-fold (‘Hautfalte’) in the region of the medial
palpebral commissure (internal canthus) and, since the nascoptic‘ fissure is obliterated by the eighth week of embryonal life,
he must have thought that the ‘Hautfaltc’ grew into the substance of the maxilla, ultimately reaching the nasal cavity. Burdach may have had the right conception of the development of
the nasal end of the naselaerimal duct, but in the genesis of the
nasolacrimal passages from a skin-fold (‘Hautfalte’) in the region
of the medial palpebral commissure he erred (providing the writer
interprets his statement correctly). It is difficult to say what
Burdach meant by his ‘Hautfalte.’ That the anlage of these
passages comes to lie in the body of the maxilla is true, but it
comes about in an entirely different Way as Will be seen subsequently. His theory would not explain the origin of the paired
lacrimal ducts.


Erdl (’45) and Coste (’47—’59), according to Ewetzky, believed
Erdl (’45) and Coste (’47—’59), according to Ewetzky, believed that the furrow “Welche am Naseneingange beginnt und am inneren Augenwinkel miindet, auf ihrer ganzen Lange fiberbriickt und dergestalt in einem Canal verwandelt.” That the naso-optic fissure becomes constricted or shut off from the surface by its lips closing in and coalescing with each other, thus establishing the nasolacrimal connections, was indeed the accepted theory for some time. The theory is, of course, erroneous because the anlage of the passages is for some time represented by a solid plug or strand of epithelial cells which earlybecomes detached from the surface. The strand of cells becomes cord-like and acquires a lumen secondarily (see subsequent paragraphs). Neither would this theory explain the pairing of the lacrimal duets.
that the furrow “Welche am Naseneingange beginnt und am
inneren Augenwinkel miindet, auf ihrer ganzen Lange fiberbriickt und dergestalt in einem Canal verwandelt.” That the
naso-optic fissure becomes constricted or shut off from the surface by its lips closing in and coalescing with each other, thus
establishing the nasolacrimal connections, was indeed the accepted
theory for some time. The theory is, of course, erroneous because
the anlage of the passages is for some time represented by a solid
plug or strand of epithelial cells which earlybecomes detached from
the surface. The strand of cells becomes cord-like and acquires
a lumen secondarily (see subsequent paragraphs). Neither would
this theory explain the pairing of the lacrimal duets.


So far as my review of the literature would prove, Born (’76)
So far as my review of the literature would prove, Born (’76) Was the first investigator to properly interpret the earliest stages
Was the first investigator to properly interpret the earliest stages


2 Der innere Augenwinkel ist mehr verlangert als bei Erwachsenen und steht
2 Der innere Augenwinkel ist mehr verlangert als bei Erwachsenen und steht tiefcr als der aussere; schon in der achten Woe-he erscheint in ihm die Karunkel und eine zur Mudnasenhohle sich sekende I-lautfalte als Anfang des Thranenkanals. Die Thriinenpunlste ragen im fiinften Monat sehr stark l1BI'VOI‘ und im siebenten etwas mehr zuriick. GENESIS OF NASOLACRIMAL PASSAGES IN MAN 3
tiefcr als der aussere; schon in der achten Woe-he erscheint in ihm die Karunkel
und eine zur Mudnasenhohle sich sekende I-lautfalte als Anfang des Thranenkanals.
Die Thriinenpunlste ragen im fiinften Monat sehr stark l1BI'VOI‘ und im siebenten
etwas mehr zuriick.
GENESIS OF NASOLACRIMAL PASSAGES IN MAN 3


of the nasolacrimal passages. He investigated this field in amphibia and found a structure homologous with that described
of the nasolacrimal passages. He investigated this field in amphibia and found a structure homologous with that described by Coste for mammals, but he found that its genesis did not agree with Coste’s hypothesis.
by Coste for mammals, but he found that its genesis did not agree
with Coste’s hypothesis.


Since Born’s conception of the genesis of the nasolacrimal passages in amphibia applies also, broadly speaking, in other forms,
Since Born’s conception of the genesis of the nasolacrimal passages in amphibia applies also, broadly speaking, in other forms, it may not be amiss to briefly quote his own words:
it may not be amiss to briefly quote his own words:


Der Thranencanal der Amphibien bildet sich durch Einwachsung
Der Thranencanal der Amphibien bildet sich durch Einwachsung und Absehniiriing eines Epithelstreifens von der Nase bis zum Auge
und Absehniiriing eines Epithelstreifens von der Nase bis zum Auge


hin der dann ein Lumen bekonunt und sich mit der Nascnholile in
hin der dann ein Lumen bekonunt und sich mit der Nascnholile in Verbindung setzt.
Verbindung setzt.


While the above did not clear up the origin of the lacrimal
While the above did not clear up the origin of the lacrimal ducts in mammals, it nevertheless proved to be the correct interpretation of the genesis of the main portion of the nasolacrimal duct in all investigated forms up to the present. According to Born, in amphibia, a solid strand of epithelial cells, extending from the eye to the nose, becomes detached from the surface epithelium and this strand of cells later acquires a lumen. The strand of cells retains connections with the surface epithelium at both the ocular and nasal ends. This strand of cells becomes both the lacrimal ducts and the Whole of the nasolacrimal duct.
ducts in mammals, it nevertheless proved to be the correct interpretation of the genesis of the main portion of the nasolacrimal
duct in all investigated forms up to the present. According to
Born, in amphibia, a solid strand of epithelial cells, extending
from the eye to the nose, becomes detached from the surface
epithelium and this strand of cells later acquires a lumen. The
strand of cells retains connections with the surface epithelium
at both the ocular and nasal ends. This strand of cells becomes
both the lacrimal ducts and the Whole of the nasolacrimal duct.


Born later (’78) investigated lizards and birds and found that
Born later (’78) investigated lizards and birds and found that the basic principles concerning the anlage of the nasolacrimal passages in these forms agreed with What he found in amphibia. He, however, found that the cord of cells differentiated along the course of the oculo-nasal furrow; also that it differed somewhat in its further development. In both forms (lizards and birds) a solid cord of cells became isolated from the surface. In lizards the isolation was complete, i.e., there remained no connection with the surface epithelium at any point; both lacrimal ducts and the nasal end of the nasolacrimal duct developed as sprouts from the mother cord of cells. As in amphibia the lumina of these several channels Were. established later. In birds the cord of_ cells retained connection with the surface epithelium at both the ocular and nasal ends. One of the lacrimal ducts, however, developed as a sprout from the ocular end of the mother cord of cells. 4 J. PARSONS SCHAEFFER
the basic principles concerning the anlage of the nasolacrimal
passages in these forms agreed with What he found in amphibia.
He, however, found that the cord of cells differentiated along
the course of the oculo-nasal furrow; also that it differed somewhat
in its further development. In both forms (lizards and birds)
a solid cord of cells became isolated from the surface. In lizards
the isolation was complete, i.e., there remained no connection
with the surface epithelium at any point; both lacrimal ducts
and the nasal end of the nasolacrimal duct developed as sprouts
from the mother cord of cells. As in amphibia the lumina of
these several channels Were. established later. In birds the cord
of_ cells retained connection with the surface epithelium at both
the ocular and nasal ends. One of the lacrimal ducts, however,
developed as a sprout from the ocular end of the mother cord of
cells.
4 J. PARSONS SCHAEFFER


Ewetzky (’7 9) studied the embryology of the nasolacrimal
Ewetzky (’7 9) studied the embryology of the nasolacrimal connections in ‘Rindscmbryonen’ and in the main agreed with B0rn’s findings.
connections in ‘Rindscmbryonen’ and in the main agreed with
B0rn’s findings.


Born (’82) investigated reptiles and found that the solid cord
Born (’82) investigated reptiles and found that the solid cord or strand of epithelial cells retained connection with the surface epithelium at the ocular end, but that the nasal end of the nasclacrimal duct grew a sprout from the mother cord of cells. He also found that there is no doubling or pairing at the ocular end; that is, he found but one lacrimal duct.
or strand of epithelial cells retained connection with the surface
epithelium at the ocular end, but that the nasal end of the nasclacrimal duct grew a sprout from the mother cord of cells.
He also found that there is no doubling or pairing at the ocular
end; that is, he found but one lacrimal duct.


Legal (’83) investigated the pig and came to the same general
Legal (’83) investigated the pig and came to the same general conclusion as did Born, and claimed (for pig) that the superior lacrimal duct was Wholly a part of the original mother cord of cells. He further claimed that the mother cord of cells retained superiorly and dorsally a connection with the epidermis in the region of the palpebral fissure.3 He concluded that the inferiorlacrimal duct grew as a sprout from the mother cord, but he found that the sprout did not reach the free border of the inferior eyelid; therefore remaining ‘funktionell unbrauchbarfi
conclusion as did Born, and claimed (for pig) that the superior
lacrimal duct was Wholly a part of the original mother cord of
cells. He further claimed that the mother cord of cells retained
superiorly and dorsally a connection with the epidermis in the
region of the palpebral fissure.3 He concluded that the inferiorlacrimal duct grew as a sprout from the mother cord, but he
found that the sprout did not reach the free border of the inferior
eyelid; therefore remaining ‘funktionell unbrauchbarfi


Kolliker C84) believed that both lacrimal ducts developed as
Kolliker C84) believed that both lacrimal ducts developed as sprouts from the mother cord.
sprouts from the mother cord.


Ewetzky (’88) thought that the ocular end of the mother cord
Ewetzky (’88) thought that the ocular end of the mother cord divided into two forks, and that these forks in turn developed into the lacrimal ducts (superior and inferior).
divided into two forks, and that these forks in turn developed into
the lacrimal ducts (superior and inferior).


J ouves (’97) studied the sheep and man, and found in a 19 mm.
J ouves (’97) studied the sheep and man, and found in a 19 mm. human embryo both lacrimal ducts present but without any connection with the surface epithelium at this time.
human embryo both lacrimal ducts present but without any connection with the surface epithelium at this time.


Cosmettatos (’98) investigated the rabbit, and Staneuleanu
Cosmettatos (’98) investigated the rabbit, and Staneuleanu (’00) the bird, the sheep, and man. These investigators, accord 3 . . . . ganz hinten cndlich bleibt bestandig cine Verbindung mit der Lidfurche erhalten.
(’00) the bird, the sheep, and man. These investigators, accord
3 . . . . ganz hinten cndlich bleibt bestandig cine Verbindung mit der
Lidfurche erhalten.


4 Bei Schweinscmbryonen ist die Tl1ranenl<analanlage eine solide, Von der
4 Bei Schweinscmbryonen ist die Tl1ranenl<analanlage eine solide, Von der tiefen Epidermisschicht des Thrancnfurchengrundes ins Bindegewebe einwucl1crnde Leiste, die sich bis auf das hinterste Ende am innern Augenwinkel von der Epidermis absehniirt, und mit dem vordern, stark auswachsendcn Ende mit der Nasenhohle verbindct: der abgeloste, solide Epithelstrang stellt den spatern einfachen Thranennasengang und das obere Thranenrijrchen dar, das untere sprosst aus demselben hcrvor, bleibt aber, da cs die freie liidfltiche nicht erreicht, funktionell unbrauehbar. GENESIS OF NASOLACRIMAL PASSAGES IN MAN 5
tiefen Epidermisschicht des Thrancnfurchengrundes ins Bindegewebe einwucl1crnde Leiste, die sich bis auf das hinterste Ende am innern Augenwinkel von der
Epidermis absehniirt, und mit dem vordern, stark auswachsendcn Ende mit der
Nasenhohle verbindct: der abgeloste, solide Epithelstrang stellt den spatern
einfachen Thranennasengang und das obere Thranenrijrchen dar, das untere
sprosst aus demselben hcrvor, bleibt aber, da cs die freie liidfltiche nicht erreicht,
funktionell unbrauehbar.
GENESIS OF NASOLACRIMAL PASSAGES IN MAN 5


ing to Fleisher, depending upon the form studied, came to the
ing to Fleisher, depending upon the form studied, came to the conclusion that one of the two lacrimal ducts was wholly or partly a portion of the original mother cord of cells, and that the other lacrimal duct and the remaining portion of the nasolacrimal duet developed as sprouts from the mother cord.
conclusion that one of the two lacrimal ducts was wholly or partly
a portion of the original mother cord of cells, and that the other
lacrimal duct and the remaining portion of the nasolacrimal duet
developed as sprouts from the mother cord.


Hammar (’02) shows a model5 of a human embryo 18.5 mm.
Hammar (’02) shows a model5 of a human embryo 18.5 mm. long in which both the nasal and ocular ends of the anlage of the nasolacrimal passages are free from the surface epithelium. The anlages of the laerimal ducts are well illustrated in the model.
long in which both the nasal and ocular ends of the anlage of the
nasolacrimal passages are free from the surface epithelium. The
anlages of the laerimal ducts are well illustrated in the model.


Fleisher (’06) published his researches on the pig, the guinea
Fleisher (’06) published his researches on the pig, the guinea pig, the mouse, the rabbit, and man. He arrived at the following general conclusion:
pig, the mouse, the rabbit, and man. He arrived at the following general conclusion:


Aus diesen Praparaten geht hervor, (lass beim Menschen die Entwieklung der Tranenrohrchen in derselben Weise vor sich geht, wie
Aus diesen Praparaten geht hervor, (lass beim Menschen die Entwieklung der Tranenrohrchen in derselben Weise vor sich geht, wie bei den anderen, von mir untersuehten Saugetiercn, durch selbstandige Sprossung jedes der Rorchen aus dem Augencnde der Triinenleiste, die sieh vollstandig voin Epithel abschniirt.
bei den anderen, von mir untersuehten Saugetiercn, durch selbstandige
Sprossung jedes der Rorchen aus dem Augencnde der Triinenleiste,
die sieh vollstandig voin Epithel abschniirt.


Fleisher, therefore, disagrees with Legal and some others on the
Fleisher, therefore, disagrees with Legal and some others on the genesis of the lacrimal duets (lachrymal canaliculi), and conforms with Kolliker and more nearly to Ewetzky. He is also in accord with Matys who came to similar conclusions for Spermophillus citillus.
genesis of the lacrimal duets (lachrymal canaliculi), and conforms
with Kolliker and more nearly to Ewetzky. He is also in accord
with Matys who came to similar conclusions for Spermophillus
citillus.


Lang (’11) reports his findings in a human embryo, aged from
Lang (’11) reports his findings in a human embryo, aged from seven to eight weeks. He finds that the left side of his embryo agrees with the conclusions of Fleisher and Matys. On the right side he, however, finds the superior lacrimal—duct anlage wanting.
seven to eight weeks. He finds that the left side of his embryo
agrees with the conclusions of Fleisher and Matys. On the right
side he, however, finds the superior lacrimal—duct anlage wanting.


In subsequent portions of this paper I wish to record my preliminary observations on the genesis and development of the
In subsequent portions of this paper I wish to record my preliminary observations on the genesis and development of the nasolacrimal passages in man. I now hope to carry this study farther and, if an investigation of a larger number of human embryos warrants, will report my later observations and conclusions in a subsequent paper.
nasolacrimal passages in man. I now hope to carry this study
farther and, if an investigation of a larger number of human
embryos warrants, will report my later observations and conclusions in a subsequent paper.


In looking over material for the substance of another paper
In looking over material for the substance of another paper I noticed variations in the development of some portions of the
I noticed variations in the development of some portions of the


5 Studien fiber die Entwicklung des Vorderd-arms und einiger angrenzenclen
5 Studien fiber die Entwicklung des Vorderd-arms und einiger angrenzenclen Organe, Archiv f. mikrosk. A11at., Bd. 59, taf. 26, fig. 14. 6 J. PARSONS SCHAEFFER
Organe, Archiv f. mikrosk. A11at., Bd. 59, taf. 26, fig. 14.
6 J. PARSONS SCHAEFFER


nasolacrimal passages. I, therefore, felt that there was need of
nasolacrimal passages. I, therefore, felt that there was need of an investigation of the genesis of these passages in man, based upon an examination of a larger number of human embryos than was formerly done. Fortunately there were available for this study good series of appropriately aged embryos showing the genesis and early stages of the nasolacrimal passages. The embryos ranged in age from thirty days to ‘term.’ A certain amount of material of the early extra-uterine period was also studied; ‘together with a large number of adult specimens.
an investigation of the genesis of these passages in man, based
upon an examination of a larger number of human embryos than
was formerly done. Fortunately there were available for this
study good series of appropriately aged embryos showing the
genesis and early stages of the nasolacrimal passages. The
embryos ranged in age from thirty days to ‘term.’ A certain
amount of material of the early extra-uterine period was also
studied; ‘together with a large number of adult specimens.


It is well known that at one stage of the embryo there is a
It is well known that at one stage of the embryo there is a furrow or fissurc—the naso—optic fissure—extending from the eye to the nasal pit. This fissure is bounded superiorly by the lateral nasal process and inferiorly by the maxillary process. The nasooptic fissure gradually disappears by a growth and coalescence of the structures bordering it. Inthis manner the fissure is ‘out—folded’ as it were and thus becomes shallower and shallower until its ultimate obliteration. The epidermis along the course of the floor of the now very rudimentary fissure concerns us for some time longer with reference to the anlage of the nasolacrimal passages.
furrow or fissurc—the naso—optic fissure—extending from the eye
to the nasal pit. This fissure is bounded superiorly by the lateral
nasal process and inferiorly by the maxillary process. The nasooptic fissure gradually disappears by a growth and coalescence
of the structures bordering it. Inthis manner the fissure is
‘out—folded’ as it were and thus becomes shallower and shallower
until its ultimate obliteration. The epidermis along the course
of the floor of the now very rudimentary fissure concerns us for
some time longer with reference to the anlage of the nasolacrimal
passages.


Before the naso—optic fissure is entirely obliterated We have in
Before the naso—optic fissure is entirely obliterated We have in frontal sections a thickening of the deeper layers of the epidermis along the floor of the very rudimentary fissure (fig. 2). This initial thickening is the anlage of the nasolacrimal passages. It is at first, and remains so for some time, a solid cord—like structure of epidermal cells, at all points a part of the epidermis, along the floor of the remains of the naso—optic furrow, extending from the neighborhood of the eye towards the nose.
frontal sections a thickening of the deeper layers of the epidermis
along the floor of the very rudimentary fissure (fig. 2). This
initial thickening is the anlage of the nasolacrimal passages. It
is at first, and remains so for some time, a solid cord—like structure of epidermal cells, at all points a part of the epidermis, along
the floor of the remains of the naso—optic furrow, extending from
the neighborhood of the eye towards the nose.


My observations began on embryos aged approximately from
My observations began on embryos aged approximately from thirty to thirty—two days. In these embryos I could find no evidence whatever of an anlage of the nasolacrimal passages. ‘In fig. 1 we have a frontal section through the remains of the naso—optic fissure (human embryo aged approximately thirtythree days). Note that there is no evidence of the anlage of the nasolacrimal passages along the floor of the rudimenatry fissure. The epidermis appears uniform in thickness at all points, i.e., the epidermis is not thickened along the floor of the fissure. GENESIS OF NASOLACRIMAL PASSAGES IN MAN 7
thirty to thirty—two days. In these embryos I could find no
evidence whatever of an anlage of the nasolacrimal passages.
‘In fig. 1 we have a frontal section through the remains of the
naso—optic fissure (human embryo aged approximately thirtythree days). Note that there is no evidence of the anlage of the
nasolacrimal passages along the floor of the rudimenatry fissure.
The epidermis appears uniform in thickness at all points, i.e.,
the epidermis is not thickened along the floor of the fissure.
GENESIS OF NASOLACRIMAL PASSAGES IN MAN 7




Fig. 1 Frontal section through the nasal fossa (f) and the now-rudimentary
Fig. 1 Frontal section through the nasal fossa (f) and the now-rudimentary naso-optic furrow (-no), from a human embryo aged approximately thirty-three days. Note that there is no evidence of thickening of the epidermis along the floor of the rudimentary naso-optic furrow (no), to establish the anlage of the nasolacriinal passages. X 62.4
naso-optic furrow (-no), from a human embryo aged approximately thirty-three
days. Note that there is no evidence of thickening of the epidermis along the
floor of the rudimentary naso-optic furrow (no), to establish the anlage of the
nasolacriinal passages. X 62.4


Fig. 2 A similar section to that illustrated in fig. 1, from a human embryo aged
Fig. 2 A similar section to that illustrated in fig. 1, from a human embryo aged thirty-four days. Note the plug—like thickening of the epidermis in the position of the rudimentary naso—optic furrow. This is the first evidence of the anlage of the nasolaerimal passages. X 62.4.
thirty-four days. Note the plug—like thickening of the epidermis in the position
of the rudimentary naso—optic furrow. This is the first evidence of the anlage
of the nasolaerimal passages. X 62.4.


Fig.3 A corresponding section to those illustrated in figs. 1 and 2, from a
Fig.3 A corresponding section to those illustrated in figs. 1 and 2, from a human embryo aged approximately thirty—five days. Note the marked in-growth of the epidermal plug in comparison to the plug represented in fig. 2. X 62.4.
human embryo aged approximately thirty—five days. Note the marked in-growth
of the epidermal plug in comparison to the plug represented in fig. 2. X 62.4.


Fig. 4 A frontal section through the anlage of the nasolacrimal passages,
Fig. 4 A frontal section through the anlage of the nasolacrimal passages, from a human embryo aged forty-three days. Note that the cord of epidermal cells is now entirely separated from the surface. It is wholly surrounded by mesenchymal cells. In the sections preceding and following this the separation from the surface was just as complete as in that shown here. X 62.4.
from a human embryo aged forty-three days. Note that the cord of epidermal
cells is now entirely separated from the surface. It is wholly surrounded by
mesenchymal cells. In the sections preceding and following this the separation
from the surface was just as complete as in that shown here. X 62.4.


The first evidences of the anlage of these passages I found in a
The first evidences of the anlage of these passages I found in a 12 mm. embryo, aged about thirty-four days. The anlage is well illustrated in figs. 2 and 7 as a plug—like thickening (in frontal section) of the deeper layers of the epidermis along the floor of the remains of the naso—optie fissure. Note especially that the surface layer of flat epidermal cells is not included in the anlage 8 J. PARSONS SCHAEFFER
12 mm. embryo, aged about thirty-four days. The anlage is
well illustrated in figs. 2 and 7 as a plug—like thickening (in frontal
section) of the deeper layers of the epidermis along the floor of
the remains of the naso—optie fissure. Note especially that the
surface layer of flat epidermal cells is not included in the anlage
8 J. PARSONS SCHAEFFER


of the nasolacrimal passages. In this respect I am in accord with
of the nasolacrimal passages. In this respect I am in accord with Born, Legal and others and at variance with Evvetzky’s first paper (’79). As to age for the first evidences of the anlage of the nasolacrimal passages I agree rather closely with Ewetzky, who
Born, Legal and others and at variance with Evvetzky’s first
paper (’79). As to age for the first evidences of the anlage of the
nasolacrimal passages I agree rather closely with Ewetzky, who


   
 


Fbua cram‘
rmterwr


 
Fbua cram‘ rmterwr


Tlcatus nllsf
inferior


Con. n_as.
mferzor


Tlcatus nllsf inferior


Fig. 5 Selected sections from a series through the developing nasolacrimal
Con. n_as. mferzor
passages (human embryo aged from forty-three to forty-live days). Note that
nowhere are the anlages of the nasolaerimal passages in connection with the surface. The laerimal ducts are already in evidence. All of the ‘passages’ are yet
solid cords of epithelial cells, and are indicated in deep black. X 14.


found that “die Entwickelung des Thraneneanals beginnt um
das Ende der 5. oder im Anfang; der 6. Woche des F otallebens.”
The anlage of the nasolaerimal passages soon becomes sufficiently developed to sink into the cerium along the course of
the rudimentary naso—optie fissure. The anlage grows rapidly
GENESIS OF NASOLACRIMAL PASSAGES IN MAN 9


and in a brief time it has grown to such an extent that it reaches
Fig. 5 Selected sections from a series through the developing nasolacrimal passages (human embryo aged from forty-three to forty-live days). Note that nowhere are the anlages of the nasolaerimal passages in connection with the surface. The laerimal ducts are already in evidence. All of the ‘passages’ are yet solid cords of epithelial cells, and are indicated in deep black. X 14.
into the underlying mesenehyrnal tissue. VVitness for example
figs. 3 and 8, which represent frontal sections through theileft
nasal fossa of an embryo aged approximately thirty-five days.
In these figures the ridge of epithelial cells has grown into the
underlying mesenchyrnal tissue. Note especially, however, that
the anlage still retains its connection with the rete mucosum
of the epidermis along the course of the naso-optic groove, in
which it has its genesis. Note further that the anlage is as yet
solid and that there is no evidence of lumen formation.


Fig. 9 represents a semi-frontal section through a later stage of
found that “die Entwickelung des Thraneneanals beginnt um das Ende der 5. oder im Anfang; der 6. Woche des F otallebens.The anlage of the nasolaerimal passages soon becomes sufficiently developed to sink into the cerium along the course of the rudimentary naso—optie fissure. The anlage grows rapidly GENESIS OF NASOLACRIMAL PASSAGES IN MAN 9
the anlage (embryo aged about forty-three days). Note that
now the cord of epithelial cells is entirely detached from the surface, i.e., it h.as entirely lost its connection with the rete mucosum
of the epidermis from which it arose. The anlage of the nasclacrimal passages now lies well embedded in the mesenchymal
tissue. It will be further noticed that the central cells of the
cord-like anlage (fig. 9) have taken the stain less deeply, and
apparently there is already an attempt at lumen formation. Some
of the central cells seem to be in a state of ‘neerobiosis.The
cells of the cord are apparently becoming re-arranged to form a
wall in anticipation of a later lumen.


In the serial frontal sections through the nasal cavity of a
and in a brief time it has grown to such an extent that it reaches into the underlying mesenehyrnal tissue. VVitness for example figs. 3 and 8, which represent frontal sections through theileft nasal fossa of an embryo aged approximately thirty-five days. In these figures the ridge of epithelial cells has grown into the underlying mesenchyrnal tissue. Note especially, however, that the anlage still retains its connection with the rete mucosum of the epidermis along the course of the naso-optic groove, in which it has its genesis. Note further that the anlage is as yet solid and that there is no evidence of lumen formation.
forty-three day embryo represented in figs. 10 and 11, the complete isolation from the surface of the nasolacrimal passages at
this stage of development is well illustrated. The embryo from
which these photomicrographs were made is in a splendid state
of preservation. It is human embryo no. 3 (Hess Embryo) of
the Cornell University Series. It belongs to the research collection of Professor and Mrs. Gage.


This embryo shows several Very important points in connection with the development of the nasolacrimal passages: In the
Fig. 9 represents a semi-frontal section through a later stage of the anlage (embryo aged about forty-three days). Note that now the cord of epithelial cells is entirely detached from the surface, i.e., it h.as entirely lost its connection with the rete mucosum of the epidermis from which it arose. The anlage of the nasclacrimal passages now lies well embedded in the mesenchymal tissue. It will be further noticed that the central cells of the cord-like anlage (fig. 9) have taken the stain less deeply, and apparently there is already an attempt at lumen formation. Some of the central cells seem to be in a state of ‘neerobiosis.’ The cells of the cord are apparently becoming re-arranged to form a wall in anticipation of a later lumen.
first place We find at this stage that the anlages of the nasolacrimal passages are nowhere connected with the epidermis, but that
they are entirely encompassed by mesenchyrnal tissue. In the
second place it will be noticed that the cords of cells are solid,
with here and there evidences of lumen formation. The series
10 J. PARSONS SCHAEFFER


Figs. (5, 7, 8 and 9 Photomierographs of frontal sections showing several
In the serial frontal sections through the nasal cavity of a forty-three day embryo represented in figs. 10 and 11, the complete isolation from the surface of the nasolacrimal passages at this stage of development is well illustrated. The embryo from which these photomicrographs were made is in a splendid state of preservation. It is human embryo no. 3 (Hess Embryo) of the Cornell University Series. It belongs to the research collection of Professor and Mrs. Gage.
stages in the development of the nasolacrimal passages; (1,, b, c = remains of the
 
naso-optic furrow; f=nasal fossa; e=eye; d=difl‘erent stages of the anlage of the
This embryo shows several Very important points in connection with the development of the nasolacrimal passages: In the first place We find at this stage that the anlages of the nasolacrimal passages are nowhere connected with the epidermis, but that they are entirely encompassed by mesenchyrnal tissue. In the second place it will be noticed that the cords of cells are solid, with here and there evidences of lumen formation. The series 10 J. PARSONS SCHAEFFER
nasolacrimal passages.
 
Figs. (5, 7, 8 and 9 Photomierographs of frontal sections showing several stages in the development of the nasolacrimal passages; (1,, b, c = remains of the naso-optic furrow; f=nasal fossa; e=eye; d=difl‘erent stages of the anlage of the nasolacrimal passages.


Fig. 6 Note that there is no evidence of the anlage of the nasolacriinal passages in the region of the naso-optic furrow (u.). Human embryo aged thirtythree days. X 68.
Fig. 6 Note that there is no evidence of the anlage of the nasolacriinal passages in the region of the naso-optic furrow (u.). Human embryo aged thirtythree days. X 68.


Fig. 7 Note the plug-like anlage of the uasolaerimal passages (d) from the
Fig. 7 Note the plug-like anlage of the uasolaerimal passages (d) from the deep layers of the epidermis along the floor of the naso-optic furrow (b). Human embryo aged from thirty-four to thirty-five days. X 68.
deep layers of the epidermis along the floor of the naso-optic furrow (b). Human
embryo aged from thirty-four to thirty-five days. X 68.


Fig. 8 In this section the anlage of the nasolacriinal passages is considerably
Fig. 8 In this section the anlage of the nasolacriinal passages is considerably advanced over that shown in fig. 7. Note, however, notwithstanding that it has pushed its way into the underlying mesenchymal tissue, that the anlage still retains its connection with the deeper layers of the epidermis along the floor of the naso-optic furrow ((2). Human embryo aged about thirty—six days. X68.
advanced over that shown in fig. 7. Note, however, notwithstanding that it has
pushed its way into the underlying mesenchymal tissue, that the anlage still
retains its connection with the deeper layers of the epidermis along the floor of
the naso-optic furrow ((2). Human embryo aged about thirty—six days. X68.


Fig. 9 In this section the anlage of the nasolacrimal passages has lost its connection with the surface. Human embryo aged forty-three days. X 68.
Fig. 9 In this section the anlage of the nasolacrimal passages has lost its connection with the surface. Human embryo aged forty-three days. X 68. GENESIS OF NASOLACRIMAL PASSAGES IN MAN 11
GENESIS OF NASOLACRIMAL PASSAGES IN MAN 11


Figs. 10 and 11 1’l1otomi<;1'ogra.phs of frontal sections in the region of the
Figs. 10 and 11 1’l1otomi<;1'ogra.phs of frontal sections in the region of the developing nasolaurimal passages, from a human embryo aged forty-three days. Note the anlages of the nasolacrimal passages and that they are entirely separated from the surface. The lacriinal-dU.ct anlages are Well advanced and show as sprouts from the mother cord. The nasal..end of the cord has not developed sulficiently to come in Contact with the mucous membrane. of the inferior nasal rneutus. The lacrimal ducts are also some distance from the free borders of the eyelids at this time. The section represeutocl in fig. 10 is the most ventral of the series and that represented in fig. 11 the most dorsal. Some of the intervening sections of the series are. of course, omitted. Embryo no. 3-Hess, Cornell University Series. 1; = anlage of lmsolaerimal duct; 'L'nf= anlage of inferiorlztcrimalduct; sup = anlage of superior laerimal duct; e = eye. X ‘27. 12 J. PARSONS SCHAEFFER
developing nasolaurimal passages, from a human embryo aged forty-three days.
Note the anlages of the nasolacrimal passages and that they are entirely separated
from the surface. The lacriinal-dU.ct anlages are Well advanced and show as
sprouts from the mother cord. The nasal..end of the cord has not developed sulficiently to come in Contact with the mucous membrane. of the inferior nasal rneutus.
The lacrimal ducts are also some distance from the free borders of the eyelids at
this time. The section represeutocl in fig. 10 is the most ventral of the series
and that represented in fig. 11 the most dorsal. Some of the intervening sections
of the series are. of course, omitted. Embryo no. 3-Hess, Cornell University
Series. 1; = anlage of lmsolaerimal duct; 'L'nf= anlage of inferiorlztcrimalduct;
sup = anlage of superior laerimal duct; e = eye. X ‘27.
12 J. PARSONS SCHAEFFER


also shows some irregularities and lateral buds from the main
also shows some irregularities and lateral buds from the main cords. These may account for the very common diverticula of the adult nasolacrimal duets (fig. 30). Finally the series shows that the lacrimal ducts (lachrymal canalieuli) begin as sprouts from the ocular end of the mother cord of cells. Both the superior and inferior lacrimalvducts are about equally advanced in development, but neither of them have progressed far enough to reach the free borders of the eyelids and thus establish the definitive connections between the anlages of the nasolacrimal passages and the epidermis.
cords. These may account for the very common diverticula
of the adult nasolacrimal duets (fig. 30). Finally the series shows
that the lacrimal ducts (lachrymal canalieuli) begin as sprouts
from the ocular end of the mother cord of cells. Both the superior and inferior lacrimalvducts are about equally advanced in
development, but neither of them have progressed far enough to
reach the free borders of the eyelids and thus establish the definitive connections between the anlages of the nasolacrimal passages
and the epidermis.


The lacrimal ducts are also solid cords of cells and show no
The lacrimal ducts are also solid cords of cells and show no evidence of lumen formation. In this series (figs. 10 and 11) it would indeed be diflieult to sayiwhich of the lacrimal ducts (superior or inferior) was the first to begin its budding from the mother cord. Presumably they started budding approximately at the same time.
evidence of lumen formation. In this series (figs. 10 and 11)
it would indeed be diflieult to sayiwhich of the lacrimal ducts
(superior or inferior) was the first to begin its budding from the
mother cord. Presumably they started budding approximately
at the same time.


So far as my observations would prove there is considerable
So far as my observations would prove there is considerable variation in the development of the laerimal ducts, notwithstanding that both ducts begin, I believe, as buds from the mother cords of cells. The two ducts do not always begin their development at the same time. If they do begin at the same time then one or the other is often relatively tardy in its growth.
variation in the development of the laerimal ducts, notwithstanding that both ducts begin, I believe, as buds from the mother
cords of cells. The two ducts do not always begin their development at the same time. If they do begin at the same time
then one or the other is often relatively tardy in its growth.


In figs. 12 and 13 are represented frontal sections through the
In figs. 12 and 13 are represented frontal sections through the nasal cavity of a forty—two to forty-five day embryo. On the left side of this embryo (figs. 12 and 13) the superior lacrimal duct is well advanced, almost reaching to the free border of the eyelid. The inferior lacrimal duct on the other hand is extremely backward in its development. The only structure present—a small lateral bud from the mother cord of cells, that may be the beginning of the inferior lacrimal duct, is shown in fig. 12. I, however, am not at all sure that this is the anlage of the inferior duet. It is a well known fact that one or the other lacrimal-duct anlage may fail to reach the free border of the eyelid. It is, therefore, possible, had this embryo (figs. 12 and 13) continued its development to ‘term,’ that it would have been born without a drainage duct for the inferior eyelid. On the other hand, on GENESIS or NASOLACRIMAL PASSAGES IN MAN 13
nasal cavity of a forty—two to forty-five day embryo. On the
left side of this embryo (figs. 12 and 13) the superior lacrimal
duct is well advanced, almost reaching to the free border of the
eyelid. The inferior lacrimal duct on the other hand is extremely
backward in its development. The only structure present—a
small lateral bud from the mother cord of cells, that may be the
beginning of the inferior lacrimal duct, is shown in fig. 12. I,
however, am not at all sure that this is the anlage of the inferior
duet. It is a well known fact that one or the other lacrimal-duct
anlage may fail to reach the free border of the eyelid. It is,
therefore, possible, had this embryo (figs. 12 and 13) continued
its development to ‘term,’ that it would have been born without
a drainage duct for the inferior eyelid. On the other hand, on
GENESIS or NASOLACRIMAL PASSAGES IN MAN 13


the right side of the same embryo both lacrimal—duct anlages are
the right side of the same embryo both lacrimal—duct anlages are equally developed.
equally developed.


To say, from the condition found in the embryo represented
To say, from the condition found in the embryo represented in figs. 12 and 13, that the superior laerimal—duet anlage is a portion of the original mother cord of cells is I believe erroneous. I rather hold, in such cases, that the infer-ior—duet anlage is tardy in its development, and that both duets have their anlages in buds from the mother cord. Of course as stated above one or the other duct may at times. for unknown reasons, fail to develop far enough to gain coalescence with the free border of the eyelid;
in figs. 12 and 13, that the superior laerimal—duet anlage is a portion of the original mother cord of cells is I believe erroneous.
I rather hold, in such cases, that the infer-ior—duet anlage is tardy
in its development, and that both duets have their anlages in
buds from the mother cord. Of course as stated above one or
the other duct may at times. for unknown reasons, fail to develop
far enough to gain coalescence with the free border of the eyelid;




Figs. 12 and 13 Pliotomicrographs of frontal sections of a human embryo aged
Figs. 12 and 13 Pliotomicrographs of frontal sections of a human embryo aged forty-two to forty-five days, in the region of the early lacrimal passages of the left side. Note that the superior laerimal duct (sld) is well advanced. The only evidence of an inferior duct is seen in fig. 12, at point marked X. Whether this early condition would have led to an absence of the inferior lacrirnal duct is of course not known. slcl = superior lacriinalduct; as = anlage (17) of inferior lacrimal duet. X 32.
forty-two to forty-five days, in the region of the early lacrimal passages of the
left side. Note that the superior laerimal duct (sld) is well advanced. The only
evidence of an inferior duct is seen in fig. 12, at point marked X. Whether this
early condition would have led to an absence of the inferior lacrirnal duct is of
course not known. slcl = superior lacriinalduct; as = anlage (17) of inferior lacrimal
duet. X 32.


or the duct may reach the border of the lid but-fail to establish
or the duct may reach the border of the lid but-fail to establish a lumen at this point. Cases have also been reported in which supernumerary lacrimal puncta and lacrimal ducts were present (Weber and others). There are at times small buds arising,‘ from the lacrimal-duct anlages, and in all probability these at times continue to develop independently until they reach and gain coalescence with the eyelids. The lumina for these super-numerary laerimal ducts are, of course, established just as they are in the regular ducts. 14 J. PARSONS SCHAEFFER
a lumen at this point. Cases have also been reported in which
supernumerary lacrimal puncta and lacrimal ducts were present
(Weber and others). There are at times small buds arising,‘ from
the lacrimal-duct anlages, and in all probability these at times
continue to develop independently until they reach and gain
coalescence with the eyelids. The lumina for these super-numerary laerimal ducts are, of course, established just as they
are in the regular ducts.
14 J. PARSONS SCHAEFFER


By the beginning of the third month (in some cases before)
By the beginning of the third month (in some cases before) the lacrimal-duct cords have developed sufficiently to come in contact with the epithelium on the free borders of the eyelids. VVe will, however, find that the ducts are as yet in places solid cords. Portions of the mother cord, especially the portion that is destined to become a portion of the lacrimal sac, are active in lumen formation at this time. The fundus of the lacrimal sac apparently develops as a sprout from the mother cord. The nasal end of the mother cord has not developed sufficiently to come in contact with the mucous membrane of the inferior nasal meatus. It is, however, not far removed, and in a laterstage embryo it will be found coalesced with the nasal mucous membrane. Lumen formation at the point of coalescence of the mother cord with the nasal mucous membrane is delayed approximately until ‘term’ (figs. 22, 23 and 24).
the lacrimal-duct cords have developed sufficiently to come in
contact with the epithelium on the free borders of the eyelids.
VVe will, however, find that the ducts are as yet in places solid
cords. Portions of the mother cord, especially the portion that
is destined to become a portion of the lacrimal sac, are active in
lumen formation at this time. The fundus of the lacrimal sac
apparently develops as a sprout from the mother cord. The
nasal end of the mother cord has not developed sufficiently to
come in contact with the mucous membrane of the inferior
nasal meatus. It is, however, not far removed, and in a laterstage embryo it will be found coalesced with the nasal mucous
membrane. Lumen formation at the point of coalescence of the
mother cord with the nasal mucous membrane is delayed approximately until ‘term’ (figs. 22, 23 and 24).


Frontal sections of embryos aged approximately one hundred
Frontal sections of embryos aged approximately one hundred days will show that the nasal end of the mother cord of cells has developed to the nasal mucous membrane and has coalesced with it. Both laerimal—duct cords have grown to the free borders of the eyelids and have coalesced with the epithelium at these points. The mother cord of cells, or the portion destined to become the greater portions of the laerimal sac and the nasolacrimal duct, has by this time established irregular lumina at various points. The latter are best developed at the ocular end of the primary cord and towards the nasal end of the Cord. The lacrimal—duct cords have also established lumina at various points, especially in the regions of the knees, or what will later become the ampullae of the laerimal ducts.
days will show that the nasal end of the mother cord of cells has
developed to the nasal mucous membrane and has coalesced with
it. Both laerimal—duct cords have grown to the free borders of
the eyelids and have coalesced with the epithelium at these points.
The mother cord of cells, or the portion destined to become the
greater portions of the laerimal sac and the nasolacrimal duct,
has by this time established irregular lumina at various points.
The latter are best developed at the ocular end of the primary
cord and towards the nasal end of the Cord. The lacrimal—duct
cords have also established lumina at various points, especially
in the regions of the knees, or what will later become the ampullae
of the laerimal ducts.


In figs. 14, 15 and 16 (embryo aged one hundred and seven days)
In figs. 14, 15 and 16 (embryo aged one hundred and seven days) is well illustrated the irregular manner in which the cords of epi Figs. 14, 15, and 16 Photomierographs of frontal sections through the nascIaerirnal passages of a human embryo aged one hundred and seven days. Note both laerimal duets (fig. 14) in contact and fused with the epidermis in the region of the free borders of the eyelids. The laerimal ducts have not yet established lurnina in the regions of the eyelids (fig. 14). The remaining portions of the ducts are more orless patent throughout. Note the irregularity of lumen formation in the nasolaerimal duet (fig. 16). std = superior laerimal duct; 1'ld= inferiorlaerimalduet; cld = common laerirnal duet; ls = laerimal sac; nld = nasolacrimal duct. X 10.5. GENESIS OF NASOLACRIMAL PASSAGES IN MAN 15 16 J. PARSONS SCHAEFFER
is well illustrated the irregular manner in which the cords of epi
Figs. 14, 15, and 16 Photomierographs of frontal sections through the nascIaerirnal passages of a human embryo aged one hundred and seven days. Note
both laerimal duets (fig. 14) in contact and fused with the epidermis in the region
of the free borders of the eyelids. The laerimal ducts have not yet established
lurnina in the regions of the eyelids (fig. 14). The remaining portions of the ducts
are more orless patent throughout. Note the irregularity of lumen formation in
the nasolaerimal duet (fig. 16). std = superior laerimal duct; 1'ld= inferiorlaerimalduet; cld = common laerirnal duet; ls = laerimal sac; nld = nasolacrimal duct.
X 10.5.
GENESIS OF NASOLACRIMAL PASSAGES IN MAN 15
16 J. PARSONS SCHAEFFER


thelial cells establish lumina. Note that the lacrimal ducts are
thelial cells establish lumina. Note that the lacrimal ducts are more or less patent throughout, save at the free borders of the eyelids where solid cords still persist. The horizontal and vertical portions of the lacrimal ducts are well shown (fig. 14). The lacrimal sac (fig. 15) is well advanced but the remainder of the nasolaerimal duct is not wholly patent. Even at this early stage there is some evidence of beginning diverticula from the .nasolacrimal duct (fig. 16). The connection with the inferior nasal meatus is, of course, not yet established (fig. 16).
more or less patent throughout, save at the free borders of the
eyelids where solid cords still persist. The horizontal and vertical portions of the lacrimal ducts are well shown (fig. 14). The
lacrimal sac (fig. 15) is well advanced but the remainder of the
nasolaerimal duct is not wholly patent. Even at this early stage
there is some evidence of beginning diverticula from the .nasolacrimal duct (fig. 16). The connection with the inferior nasal
meatus is, of course, not yet established (fig. 16).


According to my studies, the ocular end of the mother cord
According to my studies, the ocular end of the mother cord is the first to establish a lumen. The horizontal portions of the lacrimal ducts become patent before the vertical portions (figs. 14 and 17). The last parts of the vertical portions of the lacrimal ducts to become patent are the junction points between the laerimal-duct cords and the epithelium of the free borders of the eyelids (fig. 17). The nasal end of the mother cord establishes a lumen before the middle portion of the cord (figs. 19 and 20). The middle portion remains solid, according to my series of embryos, for some time longer (fig. 19). The last portion of the nasolacrimal passages to become patent is at the point of coalescence between the nasal sprout of the mother cord and the nasal mucous membrane. This is usually deferred, as stated before, until ‘term’ or even later (fig. 24).
is the first to establish a lumen. The horizontal portions of the
lacrimal ducts become patent before the vertical portions (figs.
14 and 17). The last parts of the vertical portions of the lacrimal ducts to become patent are the junction points between the
laerimal-duct cords and the epithelium of the free borders of the
eyelids (fig. 17). The nasal end of the mother cord establishes
a lumen before the middle portion of the cord (figs. 19 and 20).
The middle portion remains solid, according to my series of
embryos, for some time longer (fig. 19). The last portion of the
nasolacrimal passages to become patent is at the point of coalescence between the nasal sprout of the mother cord and the
nasal mucous membrane. This is usually deferred, as stated
before, until ‘term’ or even later (fig. 24).


In the adult we find varying positions on the lateral wall of
In the adult we find varying positions on the lateral wall of the inferior nasal meatus for the ostium of the nasolacrimal duct. The ostium also varies as to shape, and it is occasionally duplicated. Rarely we find a triplicity of the ostium.
the inferior nasal meatus for the ostium of the nasolacrimal
duct. The ostium also varies as to shape, and it is occasionally
duplicated. Rarely we find a triplicity of the ostium.


The position of the ostium, i.e., whether at the highest point
The position of the ostium, i.e., whether at the highest point of the inferior nasal meatus, or at varying distances below the above point on the lateral nasal wall, depends, of course, largely upon the original point of coalescence of the mother cord of cells with the nasal mucous membrane (fig. 28). At times the area of coalescence between the cord of cells and the nasal mucous membrane is rather extensive (fig. 21). In such cases, due to the irregular mode of lumen formation, two or more ostia may readily b.e formed (instead of the usual single ostium) with a bridge of intervening tissue remaining permanently. The different shapes 49] "0
of the inferior nasal meatus, or at varying distances below the
above point on the lateral nasal wall, depends, of course, largely
upon the original point of coalescence of the mother cord of cells
with the nasal mucous membrane (fig. 28). At times the area of
coalescence between the cord of cells and the nasal mucous membrane is rather extensive (fig. 21). In such cases, due to the irregular mode of lumen formation, two or more ostia may readily
b.e formed (instead of the usual single ostium) with a bridge of
intervening tissue remaining permanently. The different shapes
49] "0


s
s


Figs. 17-21 Photomicrographs of frontal zseutions thmugh the nz-Lsn1acri1na.l
Figs. 17-21 Photomicrographs of frontal zseutions thmugh the nz-Lsn1acri1na.l passages of a human embryo aged one hundred and twenty days. Note the solid portions of the lat:rin1al ducts in fig. 17. In fig. 18 we mwo a patent section (ls) of the ocular end of the nasol-rm-,1'ima1 duct, and in fig. 19 a section of the mid—portion of the nasolacrimal duct, still solid (nld). Note the well established lumen (nlrl) at the nasal end of the nasolacrimal duct in figs. 20 .~m(l 21. Note how extensive the cont-actpoint between the nasolacrimal duct and the inferior nasal meatus will be (fig. 21). sld = superior lacrimal duct; ild = inferior l3.crirn:-11 duct; ls = lacrimal sac; nlcl = nas()lac1'i111al duct; Mr: = inferior Ixusal concha; i'rz.m = inferior nasal meatus. X 19.
passages of a human embryo aged one hundred and twenty days. Note the solid
portions of the lat:rin1al ducts in fig. 17. In fig. 18 we mwo a patent section (ls)
of the ocular end of the nasol-rm-,1'ima1 duct, and in fig. 19 a section of the mid—portion of the nasolacrimal duct, still solid (nld). Note the well established lumen
(nlrl) at the nasal end of the nasolacrimal duct in figs. 20 .~m(l 21. Note how extensive the cont-actpoint between the nasolacrimal duct and the inferior nasal meatus
will be (fig. 21). sld = superior lacrimal duct; ild = inferior l3.crirn:-11 duct; ls =
lacrimal sac; nlcl = nas()lac1'i111al duct; Mr: = inferior Ixusal concha; i'rz.m = inferior
nasal meatus. X 19.


THE .Am}-‘.nIc,\.\' JOURNAL OF ANATOMY, VOL. 13, No. l
THE .Am}-‘.nIc,\.\' JOURNAL OF ANATOMY, VOL. 13, No. l


17
17 18 J. PARSONS SCHAEFFER
18 J. PARSONS SCHAEFFER


Figs. 22-27 Photomicrographs of sections through the naso1a.c1'ima.l duct.
Figs. 22-27 Photomicrographs of sections through the naso1a.c1'ima.l duct.
Line 567: Line 202:
Fig. 22 From a. term child. Note that the connection between the na.solacrimal duct and the inferior nasal meatus is not yet established. "X 3.4.
Fig. 22 From a. term child. Note that the connection between the na.solacrimal duct and the inferior nasal meatus is not yet established. "X 3.4.


Fig. 23 From a seven-month fetus. The connection between the nasolacrimal duct and the inferior nasal meatus is not established. X 6.1.
Fig. 23 From a seven-month fetus. The connection between the nasolacrimal duct and the inferior nasal meatus is not established. X 6.1.  
GENESIS or NASOLACRIMAL PASSAGES IN MAN 19
 
2
<
-.
 
 
 
/..n‘rrrI.’ :1 41/’!
 


Fig. 24 From a term child. Barrier between the i'iasolacrima.l duct and the
Fig. 24 From a term child. Barrier between the i'iasolacrima.l duct and the inferior nasal mcatus still present. Note the irregularity of the nasolacrimal duct. Compare with fig. 30. X 2.9.
inferior nasal mcatus still present. Note the irregularity of the nasolacrimal
duct. Compare with fig. 30. X 2.9.


Fig. 25 From an adult aged sixty years. Note the circular and regular condition of the nasolaerirhal duct. Reconstruction seen in fig. 29. X 2.6.
Fig. 25 From an adult aged sixty years. Note the circular and regular condition of the nasolaerirhal duct. Reconstruction seen in fig. 29. X 2.6.


Fig. 26 From an adult aged sixty-five years. Note the marked diverticulum
Fig. 26 From an adult aged sixty-five years. Note the marked diverticulum (X) from the nasolacrimal duct. The nasolacrimal passages of this individual are seen in reconstruction in figs. 30 and 31. X 2.6.
(X) from the nasolacrimal duct. The nasolacrimal passages of this individual
are seen in reconstruction in figs. 30 and 31. X 2.6.


Fig. 27 From an adult aged seventy years. In the region of the ostium of
Fig. 27 From an adult aged seventy years. In the region of the ostium of the common lam-imal duct. X 2.8.
the common lam-imal duct. X 2.8.


Fig. 28 1’hotographs of transections of tho nasolacrimal duet at the point of
Fig. 28 1’hotographs of transections of tho nasolacrimal duet at the point of entrance (ostium of nasolao1'ima.l duct) into the inferior nasal meatus. Note
entrance (ostium of nasolao1'ima.l duct) into the inferior nasal meatus. Note


the different typos of ostia. (0). The sections are from adults and are magnified from two to four times.
the different typos of ostia. (0). The sections are from adults and are magnified from two to four times.
20


lag. 29
lag. 29


years.
years. and 31.
and 31.
 
J. PARSONS SCHAEFFER
 
I{.acon.=Jt1'uction 01' L110 nasolacrimal passages of an adult aged sixty
Note the regularity of the nasolacrimal duct. and compare with figs. 30
X 3.2.
GENESIS OF NASOLACRIMAL PASSAGES IN MAN


31


Figs. 30 and 31 Reconstruction of the nasolacrirnal passages of an adult aged
I{.acon.=Jt1'uction 01' L110 nasolacrimal passages of an adult aged sixty Note the regularity of the nasolacrimal duct. and compare with figs. 30 X 3.2.  
sixty-five years. Fig. 30 represents a medial View and fig. 3] a lateral View of the
reconstruction. Especially note the irregularity, clue to divorticula, of the nasclacrimal duct. The portions illdicated in black at the inferior extremity of the
nasolacrimal duct is a portion of the inferior nasal meatus. X 3.2.
22 J. PARSONS SCHAEFFER


of the ostia are doubtless due to the angle at which the original
cord of cells meets the nasal mucous membrane. The position of
contact also makes a difference. If the ostium is at the highest
point of the inferior meatus, i.e., just caudal to the attachment
of the inferior nasal concha to the lateral nasal wall, the opening
of the nasolacrimal duct is usually a large, wide, open—mouthed
ostium, unguarded by folds of mucous membrane (fig. 28).
If, on the other hand, the ostium is farther caudal 011 the lateral
Wall it is usually slit—like and more or less guarded by folds of
mucous membrane (figs. 28).


Even at term the embryo presents very irregular nasolac—
Figs. 30 and 31 Reconstruction of the nasolacrirnal passages of an adult aged sixty-five years. Fig. 30 represents a medial View and fig. 3] a lateral View of the reconstruction. Especially note the irregularity, clue to divorticula, of the nasclacrimal duct. The portions illdicated in black at the inferior extremity of the nasolacrimal duct is a portion of the inferior nasal meatus. X 3.2. 22
rimal ducts (fig. 24). After birth the Walls of the ducts become
more and more regular. In the adult we very frequently find
large divertieula from the nasolacrimal duct, and these added to
other irregularities give us at times extremely irregular lumina
(figs. 30 and 31). On the other hand we find adult ducts in
which the lumina are very simple and regular (fig. 29). The
lumina of the adult laerimal ducts (lachrymal canaliculi) are generally more or less irregular.


SUMMARY
of the ostia are doubtless due to the angle at which the original cord of cells meets the nasal mucous membrane. The position of contact also makes a difference. If the ostium is at the highest point of the inferior meatus, i.e., just caudal to the attachment of the inferior nasal concha to the lateral nasal wall, the opening of the nasolacrimal duct is usually a large, wide, open—mouthed ostium, unguarded by folds of mucous membrane (fig. 28). If, on the other hand, the ostium is farther caudal 011 the lateral Wall it is usually slit—like and more or less guarded by folds of mucous membrane (figs. 28).


1. The strand of thickened epithelium~—the anlage of the naso—
laerimal passages~along the floor of the rudimentary naso-optic
fissure becomes entirely separated from the surface, and for some
time is wholly surrounded by mesenchymal tissue.


2. The strand or cord of epithelial cells thus isolated from the
Even at term the embryo presents very irregular nasolac— rimal ducts (fig. 24). After birth the Walls of the ducts become more and more regular. In the adult we very frequently find large divertieula from the nasolacrimal duct, and these added to other irregularities give us at times extremely irregular lumina (figs. 30 and 31). On the other hand we find adult ducts in which the lumina are very simple and regular (fig. 29). The lumina of the adult laerimal ducts (lachrymal canaliculi) are generally more or less irregular.
surface is for some time Without a lumen.


3. From the mother cord of cells both laerimal ducts and the
==Summary==
nasal end of the nasolacrimal duet grow as sprouts. The cephalic
portion of the laerimal sac also grows as a sprout from the mother
cord.


4. Considerable variation occurs in the development of the
# The strand of thickened epithelium—the anlage of the naso— laerimal passages along the floor of the rudimentary naso-optic fissure becomes entirely separated from the surface, and for some time is wholly surrounded by mesenchymal tissue.
lacrimal ducts, i.e., as to number, time, and degree of development.
# The strand or cord of epithelial cells thus isolated from the surface is for some time Without a lumen.
# From the mother cord of cells both laerimal ducts and the nasal end of the nasolacrimal duet grow as sprouts. The cephalic portion of the laerimal sac also grows as a sprout from the mother cord.
# Considerable variation occurs in the development of the lacrimal ducts, i.e., as to number, time, and degree of development.
# The lumina of the several portions of the nasolacrimal passages are established in an irregular manner. The ocular end of the mother cord is the first to establish a lumen. The point of coalescence between the nasal end of the cord and the mucous membrane of the inferior nasal meatus is the last to become patent —the lumen here is established approximately at ‘term’ or even later. The horizontal portions of the lacrimal ducts establish lumina before the Vertical portions.


5. The lumina of the several portions of the nasolacrimal passages are established in an irregular manner. The ocular end
GENESIS OF NASOLACRIMAL PASSAGES IN MAN


of the mother cord is the first to establish a lumen. The point
of coalescence between the nasal end of the cord and the mucous
membrane of the inferior nasal meatus is the last to become patent
—the lumen here is established approximately at ‘term’ or even
later. The horizontal portions of the lacrimal ducts establish
lumina before the Vertical portions.


1 Wish to take this opportunity for expressing grateful acknowledgment to Professors Gage and Kerr for the material placed
Wish to take this opportunity for expressing grateful acknowledgment to Professors Gage and Kerr for the material placed at my disposal in this investigation and for other courtesies extended. I am also indebted to Professor Ferris for reading the manuscript.
at my disposal in this investigation and for other courtesies
extended. I am also indebted to Professor Ferris for reading the
manuscript.


BIBLIOGRAPHY
==Bibliography==


AsK, FRITZ 1907 Tiber die Entwickclung der Caruncula lacrimalis beim Menschen, nebst Bemcrkungen uber die Entwickelung der Tiiinenrorchen
AsK, FRITZ 1907 Tiber die Entwickclung der Caruncula lacrimalis beim Menschen, nebst Bemcrkungen uber die Entwickelung der Tiiinenrorchen und der Meibomschen Drfisen. Anatom. Anz., Bd. 30.
und der Meibomschen Drfisen. Anatom. Anz., Bd. 30.


V. BAER, KARL EnxsT1828—1837 TiberEntwiokelungschichte der'1‘hiere, Konigsberg.
V. BAER, KARL EnxsT1828—1837 TiberEntwiokelungschichte der'1‘hiere, Konigsberg.
Line 688: Line 257:
BURDACH, KARL G. 1837 Die Physiologie als Erfahrungswissenschaft. Leipzig.
BURDACH, KARL G. 1837 Die Physiologie als Erfahrungswissenschaft. Leipzig.


COSMETTATOS, F. 1898 Recherehes sur le développemcnt des Voies lacrymales.
COSMETTATOS, F. 1898 Recherehes sur le développemcnt des Voies lacrymales. Thésc de Cloctorat. Paris.
Thésc de Cloctorat. Paris.


COSTE, JEA.\r J. 1847-1859 Historic générale ct particuliere du développement
COSTE, JEA.\r J. 1847-1859 Historic générale ct particuliere du développement des corps orgninsés. Paris.
des corps orgninsés. Paris.


EMMERT, E. 1876 Angeborenes Fehlen aller 4 Thréinenpunkte und Thra'nenrorehen. Archiv. f. A11gen- und Ohrcnheilk, Bd. 5.
EMMERT, E. 1876 Angeborenes Fehlen aller 4 Thréinenpunkte und Thra'nenrorehen. Archiv. f. A11gen- und Ohrcnheilk, Bd. 5.
Line 698: Line 265:
ERDL 1845 Die Entwickelnng des Menschen und des Hiihnchens im Ei. Leipzig.
ERDL 1845 Die Entwickelnng des Menschen und des Hiihnchens im Ei. Leipzig.


EWETZKY, TH. 1879 Beitrage znr Entwickelungsgeschichte des Auges. Arch.
EWETZKY, TH. 1879 Beitrage znr Entwickelungsgeschichte des Auges. Arch. f. Augenheilk., Bd. 8.
f. Augenheilk., Bd. 8.


1888 Zur Entwickolungsgeschichte des Thranennasenganges beim
1888 Zur Entwickolungsgeschichte des Thranennasenganges beim Menschen. Arehiv. f. Opth-al., Bd. 34, Ab. 1.
Menschen. Arehiv. f. Opth-al., Bd. 34, Ab. 1.


FLEISHER, B. 1906 Die Entwicklung der Thranenrorchen bei den Séiugetieren.
FLEISHER, B. 1906 Die Entwicklung der Thranenrorchen bei den Séiugetieren. Archiv. f. ()ptl1al., Bd. 62, H. 3. 24: J. PARSONS SCHAEFFER
Archiv. f. ()ptl1al., Bd. 62, H. 3.
24: J. PARSONS SCHAEFFER


HAMMAR, J. AUG. 1902 Studicn fiber die Entwicklung des Vorderdarms und
HAMMAR, J. AUG. 1902 Studicn fiber die Entwicklung des Vorderdarms und einigcr angrenzcnden Organe. Archiv. f. mikroskop. Anat. und Ent— wick1ungsch., Bd. 59.
einigcr angrenzcnden Organe. Archiv. f. mikroskop. Anat. und Ent—
wick1ungsch., Bd. 59.


JOUVES, A. 1897 Recherches sur Ie développcrnent des voies lacrynialcs chez
JOUVES, A. 1897 Recherches sur Ie développcrnent des voies lacrynialcs chez 1’e1nbryon de moutyon et 1"cxnbryon humain. Thésn de doctorat.
1’e1nbryon de moutyon et 1"cxnbryon humain. Thésn de doctorat.


Toulouse.
Toulouse.


K6LLIK1«;R, A. 1879 Entwickluxigsgeschichto dcs Mcnstthen und der hbhern
K6LLIK1«;R, A. 1879 Entwickluxigsgeschichto dcs Mcnstthen und der hbhern Tiero. Leipzig.
Tiero. Leipzig.


1884 Grundriss dcr Entwicklungsgeschichte des Menschen und der
1884 Grundriss dcr Entwicklungsgeschichte des Menschen und der h«")hern Tiere. Leipzig.
h«")hern Tiere. Leipzig.


LEGAL, E. 1883 Die Nasenhiihlcn und der ’1‘}1r§Lnennasengang der amnioten
LEGAL, E. 1883 Die Nasenhiihlcn und der ’1‘}1r§Lnennasengang der amnioten Wirbelthiere. Morphol. Jahrbuch, Bd. 8.
Wirbelthiere. Morphol. Jahrbuch, Bd. 8.


LANG, PAVL 1911 Z111‘ Entwickelung dos Thriinenausfiihrappamtes bcim Menschen. Anat. Anz., Bd. 38.
LANG, PAVL 1911 Z111‘ Entwickelung dos Thriinenausfiihrappamtes bcim Menschen. Anat. Anz., Bd. 38.


KIAGNIIS, H. 1880 Mzmgel der unLeren Thrémenpiinlctc und Wfizrzchen auf
KIAGNIIS, H. 1880 Mzmgel der unLeren Thrémenpiinlctc und Wfizrzchen auf beiden Augerl. Centralbl. f. prakt. Augenhcilk.
beiden Augerl. Centralbl. f. prakt. Augenhcilk.


MATYS, 1905-1096 Die Entwickelung der Trfmnenableitungswege. Zeitsch. f.
MATYS, 1905-1096 Die Entwickelung der Trfmnenableitungswege. Zeitsch. f. Augenhcilk, Bd., 14 u. 16.
Augenhcilk, Bd., 14 u. 16.


SCHAEFFER, J. PARSONS 1911 The lateral wall of the cavum nasi in man, with
SCHAEFFER, J. PARSONS 1911 The lateral wall of the cavum nasi in man, with especial reference to the various developmental stages. Annals of Otol. Rhinol. and Largyno1., June.
especial reference to the various developmental stages. Annals of
Otol. Rhinol. and Largyno1., June.


1911 Variations in the an-atoniy of the nzLso—1a.chrym2L1 passages. Annals of Surgery, August.
1911 Variations in the an-atoniy of the nzLso—1a.chrym2L1 passages. Annals of Surgery, August.


STANCULEANU, G. 1900 Recherches sur Ie développement des voies IB.(‘f1‘y!I12lieS
STANCULEANU, G. 1900 Recherches sur Ie développement des voies IB.(‘f1‘y!I12lieS chez Yhomxne et chez les animaux. Archiv d’0phtalm., Tom. 20.
chez Yhomxne et chez les animaux. Archiv d’0phtalm., Tom. 20.


WEBER, A. 1861 Optvhahnologischo Nliscellen und Aphorismen, 11 Zwci Féille
WEBER, A. 1861 Optvhahnologischo Nliscellen und Aphorismen, 11 Zwci Féille Von i';berz£i.h1ig(:n Canaliculi lacrylnales. Archiv f.Op1:hahn010gie, Bd. 8, Ab. 1.
Von i';berz£i.h1ig(:n Canaliculi lacrylnales. Archiv f.Op1:hahn010gie,
Bd. 8, Ab. 1.


{{Footer}}
{{Footer}}
[[Category:Historic Embryology]]
[[Category:Historic Embryology]]
[[Category:Draft]]
[[Category:Draft]]

Revision as of 08:42, 8 February 2017

Schaeffer JP. The genesis and development of the nasolacrimal passages in man. (1912) Amer. J Anat.


Embryology - 20 Apr 2024    Facebook link Pinterest link Twitter link  Expand to Translate  
Google Translate - select your language from the list shown below (this will open a new external page)

العربية | català | 中文 | 中國傳統的 | français | Deutsche | עִברִית | हिंदी | bahasa Indonesia | italiano | 日本語 | 한국어 | မြန်မာ | Pilipino | Polskie | português | ਪੰਜਾਬੀ ਦੇ | Română | русский | Español | Swahili | Svensk | ไทย | Türkçe | اردو | ייִדיש | Tiếng Việt    These external translations are automated and may not be accurate. (More? About Translations)

Schaeffer JP. The genesis and development of the nasolacrimal passages in man. (1912) Amer. J Anat. 13(1): 1-18.

Online Editor 
Mark Hill.jpg
This historic 1912 paper by Schaeffer described development of the nasolacrimal passages.


See also:


Modern Notes

Seminal Vesicle Development | Fetal Development

Genital Links: genital | Lecture - Medicine | Lecture - Science | Lecture Movie | Medicine - Practical | primordial germ cell | meiosis | endocrine gonad‎ | Genital Movies | genital abnormalities | Assisted Reproductive Technology | puberty | Category:Genital
Female | X | X inactivation | ovary | corpus luteum | oocyte | uterus | vagina | reproductive cycles | menstrual cycle | Category:Female
Male | Y | SRY | testis | spermatozoa | ductus deferens | penis | prostate | Category:Male
Historic Embryology - Genital 
General: 1901 Urinogenital Tract | 1902 The Uro-Genital System | 1904 Ovary and Testis | 1912 Urinogenital Organ Development | 1914 External Genitalia | 1921 Urogenital Development | 1921 External Genital | 1942 Sex Cords | 1953 Germ Cells | Historic Embryology Papers | Historic Disclaimer
Female: 1904 Ovary and Testis | 1904 Hymen | 1912 Urinogenital Organ Development | 1914 External Genitalia | 1914 Female | 1921 External Genital | 1927 Female Foetus 15 cm | 1927 Vagina | 1932 Postnatal Ovary
Male: 1887-88 Testis | 1904 Ovary and Testis | 1904 Leydig Cells | 1906 Testis vascular | 1909 Prostate | 1912 Prostate | 1914 External Genitalia | 1915 Cowper’s and Bartholin’s Glands | 1920 Wolffian tubules | 1935 Prepuce | 1935 Wolffian Duct | 1942 Sex Cords | 1943 Testes Descent | Historic Embryology Papers | Historic Disclaimer

Search PubMed nasolacrimal development

Historic Disclaimer - information about historic embryology pages 
Mark Hill.jpg
Pages where the terms "Historic" (textbooks, papers, people, recommendations) appear on this site, and sections within pages where this disclaimer appears, indicate that the content and scientific understanding are specific to the time of publication. This means that while some scientific descriptions are still accurate, the terminology and interpretation of the developmental mechanisms reflect the understanding at the time of original publication and those of the preceding periods, these terms, interpretations and recommendations may not reflect our current scientific understanding.     (More? Embryology History | Historic Embryology Papers)


The Genesis And Development Of The Nasolacrimal Passages In Man

J. Parsons Schaeffer

Yale University From the Anatomical Laboratories of Cornell and Yale

Thirty-One Figures

Introduction

A brief review of the literature on the nasolacrimal passages [laerimal duets (lachrymal canaliculi), lacrimal sac, nasolacrimal duct] shows that diverse views were from time to time advanced on the genesis and development of these passages Before considering the material studied in this investigation I Want to refer to some of the theories held by earlier Writers. I do not wish to give a complete resume on the history of the development, but rather in a brief manner indicate the evolution in our knowledge concerning the genesis and development of these passages.

v. Baer (’28~’37) thought that the nasolacrimal passages had their origin in a diverticulum from the ‘ Rachenhohle.’ His theoryl presumably was based upon hypothetical conclusions, since it is entirely unsupported.

Burdach (’37) in his ‘Die Physiologie als Erfahrungswissenschaft’ Writes briefly concerning the genesis of the nasolacrimal

1 Die Bildung des Thrzmenkanals (in birds) glaubte ich in einerA11ssti'1lpung der Rachenhohle, die zuerst nur wenig vor der Eustachischen Rohre liegt und sehr bald nach dieser sichtbar wird, zu erkennen, doch habc ich bisher noch nicht den gesammten Vorgang verfolgt. Uber Entwiclcolungsgeschichte der Thiere, Thiel 2, s. 116. '

Der Thranengang stillpt sich auch hier (in mammals) aus der Rachenhijhle gegen das Ange hervor und liegt Anfangs hintcr den Muscheln,~die nur, indem sie sich verlangern, sich iiber ihn ziehen. Uber‘Entwickelungsgeschichte der Thiere, Thiel 2, S. 219.

1

ram AMERICAN JOURNAL or ANATOMY, VOL. 13, so. 1 MARCH, 1912 2 J. PARSONS SCI-IAEFFER

passages, but does not state his meaning clearly? He apparently thought that the nasolaerimal passages had their origin in a diverticulum or skin-fold (‘Hautfalte’) in the region of the medial palpebral commissure (internal canthus) and, since the nascoptic‘ fissure is obliterated by the eighth week of embryonal life, he must have thought that the ‘Hautfaltc’ grew into the substance of the maxilla, ultimately reaching the nasal cavity. Burdach may have had the right conception of the development of the nasal end of the naselaerimal duct, but in the genesis of the nasolacrimal passages from a skin-fold (‘Hautfalte’) in the region of the medial palpebral commissure he erred (providing the writer interprets his statement correctly). It is difficult to say what Burdach meant by his ‘Hautfalte.’ That the anlage of these passages comes to lie in the body of the maxilla is true, but it comes about in an entirely different Way as Will be seen subsequently. His theory would not explain the origin of the paired lacrimal ducts.

Erdl (’45) and Coste (’47—’59), according to Ewetzky, believed that the furrow “Welche am Naseneingange beginnt und am inneren Augenwinkel miindet, auf ihrer ganzen Lange fiberbriickt und dergestalt in einem Canal verwandelt.” That the naso-optic fissure becomes constricted or shut off from the surface by its lips closing in and coalescing with each other, thus establishing the nasolacrimal connections, was indeed the accepted theory for some time. The theory is, of course, erroneous because the anlage of the passages is for some time represented by a solid plug or strand of epithelial cells which earlybecomes detached from the surface. The strand of cells becomes cord-like and acquires a lumen secondarily (see subsequent paragraphs). Neither would this theory explain the pairing of the lacrimal duets.

So far as my review of the literature would prove, Born (’76) Was the first investigator to properly interpret the earliest stages

2 Der innere Augenwinkel ist mehr verlangert als bei Erwachsenen und steht tiefcr als der aussere; schon in der achten Woe-he erscheint in ihm die Karunkel und eine zur Mudnasenhohle sich sekende I-lautfalte als Anfang des Thranenkanals. Die Thriinenpunlste ragen im fiinften Monat sehr stark l1BI'VOI‘ und im siebenten etwas mehr zuriick. GENESIS OF NASOLACRIMAL PASSAGES IN MAN 3

of the nasolacrimal passages. He investigated this field in amphibia and found a structure homologous with that described by Coste for mammals, but he found that its genesis did not agree with Coste’s hypothesis.

Since Born’s conception of the genesis of the nasolacrimal passages in amphibia applies also, broadly speaking, in other forms, it may not be amiss to briefly quote his own words:

Der Thranencanal der Amphibien bildet sich durch Einwachsung und Absehniiriing eines Epithelstreifens von der Nase bis zum Auge

hin der dann ein Lumen bekonunt und sich mit der Nascnholile in Verbindung setzt.

While the above did not clear up the origin of the lacrimal ducts in mammals, it nevertheless proved to be the correct interpretation of the genesis of the main portion of the nasolacrimal duct in all investigated forms up to the present. According to Born, in amphibia, a solid strand of epithelial cells, extending from the eye to the nose, becomes detached from the surface epithelium and this strand of cells later acquires a lumen. The strand of cells retains connections with the surface epithelium at both the ocular and nasal ends. This strand of cells becomes both the lacrimal ducts and the Whole of the nasolacrimal duct.

Born later (’78) investigated lizards and birds and found that the basic principles concerning the anlage of the nasolacrimal passages in these forms agreed with What he found in amphibia. He, however, found that the cord of cells differentiated along the course of the oculo-nasal furrow; also that it differed somewhat in its further development. In both forms (lizards and birds) a solid cord of cells became isolated from the surface. In lizards the isolation was complete, i.e., there remained no connection with the surface epithelium at any point; both lacrimal ducts and the nasal end of the nasolacrimal duct developed as sprouts from the mother cord of cells. As in amphibia the lumina of these several channels Were. established later. In birds the cord of_ cells retained connection with the surface epithelium at both the ocular and nasal ends. One of the lacrimal ducts, however, developed as a sprout from the ocular end of the mother cord of cells. 4 J. PARSONS SCHAEFFER

Ewetzky (’7 9) studied the embryology of the nasolacrimal connections in ‘Rindscmbryonen’ and in the main agreed with B0rn’s findings.

Born (’82) investigated reptiles and found that the solid cord or strand of epithelial cells retained connection with the surface epithelium at the ocular end, but that the nasal end of the nasclacrimal duct grew a sprout from the mother cord of cells. He also found that there is no doubling or pairing at the ocular end; that is, he found but one lacrimal duct.

Legal (’83) investigated the pig and came to the same general conclusion as did Born, and claimed (for pig) that the superior lacrimal duct was Wholly a part of the original mother cord of cells. He further claimed that the mother cord of cells retained superiorly and dorsally a connection with the epidermis in the region of the palpebral fissure.3 He concluded that the inferiorlacrimal duct grew as a sprout from the mother cord, but he found that the sprout did not reach the free border of the inferior eyelid; therefore remaining ‘funktionell unbrauchbarfi

Kolliker C84) believed that both lacrimal ducts developed as sprouts from the mother cord.

Ewetzky (’88) thought that the ocular end of the mother cord divided into two forks, and that these forks in turn developed into the lacrimal ducts (superior and inferior).

J ouves (’97) studied the sheep and man, and found in a 19 mm. human embryo both lacrimal ducts present but without any connection with the surface epithelium at this time.

Cosmettatos (’98) investigated the rabbit, and Staneuleanu (’00) the bird, the sheep, and man. These investigators, accord 3 . . . . ganz hinten cndlich bleibt bestandig cine Verbindung mit der Lidfurche erhalten.

4 Bei Schweinscmbryonen ist die Tl1ranenl<analanlage eine solide, Von der tiefen Epidermisschicht des Thrancnfurchengrundes ins Bindegewebe einwucl1crnde Leiste, die sich bis auf das hinterste Ende am innern Augenwinkel von der Epidermis absehniirt, und mit dem vordern, stark auswachsendcn Ende mit der Nasenhohle verbindct: der abgeloste, solide Epithelstrang stellt den spatern einfachen Thranennasengang und das obere Thranenrijrchen dar, das untere sprosst aus demselben hcrvor, bleibt aber, da cs die freie liidfltiche nicht erreicht, funktionell unbrauehbar. GENESIS OF NASOLACRIMAL PASSAGES IN MAN 5

ing to Fleisher, depending upon the form studied, came to the conclusion that one of the two lacrimal ducts was wholly or partly a portion of the original mother cord of cells, and that the other lacrimal duct and the remaining portion of the nasolacrimal duet developed as sprouts from the mother cord.

Hammar (’02) shows a model5 of a human embryo 18.5 mm. long in which both the nasal and ocular ends of the anlage of the nasolacrimal passages are free from the surface epithelium. The anlages of the laerimal ducts are well illustrated in the model.

Fleisher (’06) published his researches on the pig, the guinea pig, the mouse, the rabbit, and man. He arrived at the following general conclusion:

Aus diesen Praparaten geht hervor, (lass beim Menschen die Entwieklung der Tranenrohrchen in derselben Weise vor sich geht, wie bei den anderen, von mir untersuehten Saugetiercn, durch selbstandige Sprossung jedes der Rorchen aus dem Augencnde der Triinenleiste, die sieh vollstandig voin Epithel abschniirt.

Fleisher, therefore, disagrees with Legal and some others on the genesis of the lacrimal duets (lachrymal canaliculi), and conforms with Kolliker and more nearly to Ewetzky. He is also in accord with Matys who came to similar conclusions for Spermophillus citillus.

Lang (’11) reports his findings in a human embryo, aged from seven to eight weeks. He finds that the left side of his embryo agrees with the conclusions of Fleisher and Matys. On the right side he, however, finds the superior lacrimal—duct anlage wanting.

In subsequent portions of this paper I wish to record my preliminary observations on the genesis and development of the nasolacrimal passages in man. I now hope to carry this study farther and, if an investigation of a larger number of human embryos warrants, will report my later observations and conclusions in a subsequent paper.

In looking over material for the substance of another paper I noticed variations in the development of some portions of the

5 Studien fiber die Entwicklung des Vorderd-arms und einiger angrenzenclen Organe, Archiv f. mikrosk. A11at., Bd. 59, taf. 26, fig. 14. 6 J. PARSONS SCHAEFFER

nasolacrimal passages. I, therefore, felt that there was need of an investigation of the genesis of these passages in man, based upon an examination of a larger number of human embryos than was formerly done. Fortunately there were available for this study good series of appropriately aged embryos showing the genesis and early stages of the nasolacrimal passages. The embryos ranged in age from thirty days to ‘term.’ A certain amount of material of the early extra-uterine period was also studied; ‘together with a large number of adult specimens.

It is well known that at one stage of the embryo there is a furrow or fissurc—the naso—optic fissure—extending from the eye to the nasal pit. This fissure is bounded superiorly by the lateral nasal process and inferiorly by the maxillary process. The nasooptic fissure gradually disappears by a growth and coalescence of the structures bordering it. Inthis manner the fissure is ‘out—folded’ as it were and thus becomes shallower and shallower until its ultimate obliteration. The epidermis along the course of the floor of the now very rudimentary fissure concerns us for some time longer with reference to the anlage of the nasolacrimal passages.

Before the naso—optic fissure is entirely obliterated We have in frontal sections a thickening of the deeper layers of the epidermis along the floor of the very rudimentary fissure (fig. 2). This initial thickening is the anlage of the nasolacrimal passages. It is at first, and remains so for some time, a solid cord—like structure of epidermal cells, at all points a part of the epidermis, along the floor of the remains of the naso—optic furrow, extending from the neighborhood of the eye towards the nose.

My observations began on embryos aged approximately from thirty to thirty—two days. In these embryos I could find no evidence whatever of an anlage of the nasolacrimal passages. ‘In fig. 1 we have a frontal section through the remains of the naso—optic fissure (human embryo aged approximately thirtythree days). Note that there is no evidence of the anlage of the nasolacrimal passages along the floor of the rudimenatry fissure. The epidermis appears uniform in thickness at all points, i.e., the epidermis is not thickened along the floor of the fissure. GENESIS OF NASOLACRIMAL PASSAGES IN MAN 7


Fig. 1 Frontal section through the nasal fossa (f) and the now-rudimentary naso-optic furrow (-no), from a human embryo aged approximately thirty-three days. Note that there is no evidence of thickening of the epidermis along the floor of the rudimentary naso-optic furrow (no), to establish the anlage of the nasolacriinal passages. X 62.4

Fig. 2 A similar section to that illustrated in fig. 1, from a human embryo aged thirty-four days. Note the plug—like thickening of the epidermis in the position of the rudimentary naso—optic furrow. This is the first evidence of the anlage of the nasolaerimal passages. X 62.4.

Fig.3 A corresponding section to those illustrated in figs. 1 and 2, from a human embryo aged approximately thirty—five days. Note the marked in-growth of the epidermal plug in comparison to the plug represented in fig. 2. X 62.4.

Fig. 4 A frontal section through the anlage of the nasolacrimal passages, from a human embryo aged forty-three days. Note that the cord of epidermal cells is now entirely separated from the surface. It is wholly surrounded by mesenchymal cells. In the sections preceding and following this the separation from the surface was just as complete as in that shown here. X 62.4.

The first evidences of the anlage of these passages I found in a 12 mm. embryo, aged about thirty-four days. The anlage is well illustrated in figs. 2 and 7 as a plug—like thickening (in frontal section) of the deeper layers of the epidermis along the floor of the remains of the naso—optie fissure. Note especially that the surface layer of flat epidermal cells is not included in the anlage 8 J. PARSONS SCHAEFFER

of the nasolacrimal passages. In this respect I am in accord with Born, Legal and others and at variance with Evvetzky’s first paper (’79). As to age for the first evidences of the anlage of the nasolacrimal passages I agree rather closely with Ewetzky, who


Fbua cram‘ rmterwr


Tlcatus nllsf inferior

Con. n_as. mferzor


Fig. 5 Selected sections from a series through the developing nasolacrimal passages (human embryo aged from forty-three to forty-live days). Note that nowhere are the anlages of the nasolaerimal passages in connection with the surface. The laerimal ducts are already in evidence. All of the ‘passages’ are yet solid cords of epithelial cells, and are indicated in deep black. X 14.

found that “die Entwickelung des Thraneneanals beginnt um das Ende der 5. oder im Anfang; der 6. Woche des F otallebens.” The anlage of the nasolaerimal passages soon becomes sufficiently developed to sink into the cerium along the course of the rudimentary naso—optie fissure. The anlage grows rapidly GENESIS OF NASOLACRIMAL PASSAGES IN MAN 9

and in a brief time it has grown to such an extent that it reaches into the underlying mesenehyrnal tissue. VVitness for example figs. 3 and 8, which represent frontal sections through theileft nasal fossa of an embryo aged approximately thirty-five days. In these figures the ridge of epithelial cells has grown into the underlying mesenchyrnal tissue. Note especially, however, that the anlage still retains its connection with the rete mucosum of the epidermis along the course of the naso-optic groove, in which it has its genesis. Note further that the anlage is as yet solid and that there is no evidence of lumen formation.

Fig. 9 represents a semi-frontal section through a later stage of the anlage (embryo aged about forty-three days). Note that now the cord of epithelial cells is entirely detached from the surface, i.e., it h.as entirely lost its connection with the rete mucosum of the epidermis from which it arose. The anlage of the nasclacrimal passages now lies well embedded in the mesenchymal tissue. It will be further noticed that the central cells of the cord-like anlage (fig. 9) have taken the stain less deeply, and apparently there is already an attempt at lumen formation. Some of the central cells seem to be in a state of ‘neerobiosis.’ The cells of the cord are apparently becoming re-arranged to form a wall in anticipation of a later lumen.

In the serial frontal sections through the nasal cavity of a forty-three day embryo represented in figs. 10 and 11, the complete isolation from the surface of the nasolacrimal passages at this stage of development is well illustrated. The embryo from which these photomicrographs were made is in a splendid state of preservation. It is human embryo no. 3 (Hess Embryo) of the Cornell University Series. It belongs to the research collection of Professor and Mrs. Gage.

This embryo shows several Very important points in connection with the development of the nasolacrimal passages: In the first place We find at this stage that the anlages of the nasolacrimal passages are nowhere connected with the epidermis, but that they are entirely encompassed by mesenchyrnal tissue. In the second place it will be noticed that the cords of cells are solid, with here and there evidences of lumen formation. The series 10 J. PARSONS SCHAEFFER

Figs. (5, 7, 8 and 9 Photomierographs of frontal sections showing several stages in the development of the nasolacrimal passages; (1,, b, c = remains of the naso-optic furrow; f=nasal fossa; e=eye; d=difl‘erent stages of the anlage of the nasolacrimal passages.

Fig. 6 Note that there is no evidence of the anlage of the nasolacriinal passages in the region of the naso-optic furrow (u.). Human embryo aged thirtythree days. X 68.

Fig. 7 Note the plug-like anlage of the uasolaerimal passages (d) from the deep layers of the epidermis along the floor of the naso-optic furrow (b). Human embryo aged from thirty-four to thirty-five days. X 68.

Fig. 8 In this section the anlage of the nasolacriinal passages is considerably advanced over that shown in fig. 7. Note, however, notwithstanding that it has pushed its way into the underlying mesenchymal tissue, that the anlage still retains its connection with the deeper layers of the epidermis along the floor of the naso-optic furrow ((2). Human embryo aged about thirty—six days. X68.

Fig. 9 In this section the anlage of the nasolacrimal passages has lost its connection with the surface. Human embryo aged forty-three days. X 68. GENESIS OF NASOLACRIMAL PASSAGES IN MAN 11

Figs. 10 and 11 1’l1otomi<;1'ogra.phs of frontal sections in the region of the developing nasolaurimal passages, from a human embryo aged forty-three days. Note the anlages of the nasolacrimal passages and that they are entirely separated from the surface. The lacriinal-dU.ct anlages are Well advanced and show as sprouts from the mother cord. The nasal..end of the cord has not developed sulficiently to come in Contact with the mucous membrane. of the inferior nasal rneutus. The lacrimal ducts are also some distance from the free borders of the eyelids at this time. The section represeutocl in fig. 10 is the most ventral of the series and that represented in fig. 11 the most dorsal. Some of the intervening sections of the series are. of course, omitted. Embryo no. 3-Hess, Cornell University Series. 1; = anlage of lmsolaerimal duct; 'L'nf= anlage of inferiorlztcrimalduct; sup = anlage of superior laerimal duct; e = eye. X ‘27. 12 J. PARSONS SCHAEFFER

also shows some irregularities and lateral buds from the main cords. These may account for the very common diverticula of the adult nasolacrimal duets (fig. 30). Finally the series shows that the lacrimal ducts (lachrymal canalieuli) begin as sprouts from the ocular end of the mother cord of cells. Both the superior and inferior lacrimalvducts are about equally advanced in development, but neither of them have progressed far enough to reach the free borders of the eyelids and thus establish the definitive connections between the anlages of the nasolacrimal passages and the epidermis.

The lacrimal ducts are also solid cords of cells and show no evidence of lumen formation. In this series (figs. 10 and 11) it would indeed be diflieult to sayiwhich of the lacrimal ducts (superior or inferior) was the first to begin its budding from the mother cord. Presumably they started budding approximately at the same time.

So far as my observations would prove there is considerable variation in the development of the laerimal ducts, notwithstanding that both ducts begin, I believe, as buds from the mother cords of cells. The two ducts do not always begin their development at the same time. If they do begin at the same time then one or the other is often relatively tardy in its growth.

In figs. 12 and 13 are represented frontal sections through the nasal cavity of a forty—two to forty-five day embryo. On the left side of this embryo (figs. 12 and 13) the superior lacrimal duct is well advanced, almost reaching to the free border of the eyelid. The inferior lacrimal duct on the other hand is extremely backward in its development. The only structure present—a small lateral bud from the mother cord of cells, that may be the beginning of the inferior lacrimal duct, is shown in fig. 12. I, however, am not at all sure that this is the anlage of the inferior duet. It is a well known fact that one or the other lacrimal-duct anlage may fail to reach the free border of the eyelid. It is, therefore, possible, had this embryo (figs. 12 and 13) continued its development to ‘term,’ that it would have been born without a drainage duct for the inferior eyelid. On the other hand, on GENESIS or NASOLACRIMAL PASSAGES IN MAN 13

the right side of the same embryo both lacrimal—duct anlages are equally developed.

To say, from the condition found in the embryo represented in figs. 12 and 13, that the superior laerimal—duet anlage is a portion of the original mother cord of cells is I believe erroneous. I rather hold, in such cases, that the infer-ior—duet anlage is tardy in its development, and that both duets have their anlages in buds from the mother cord. Of course as stated above one or the other duct may at times. for unknown reasons, fail to develop far enough to gain coalescence with the free border of the eyelid;


Figs. 12 and 13 Pliotomicrographs of frontal sections of a human embryo aged forty-two to forty-five days, in the region of the early lacrimal passages of the left side. Note that the superior laerimal duct (sld) is well advanced. The only evidence of an inferior duct is seen in fig. 12, at point marked X. Whether this early condition would have led to an absence of the inferior lacrirnal duct is of course not known. slcl = superior lacriinalduct; as = anlage (17) of inferior lacrimal duet. X 32.

or the duct may reach the border of the lid but-fail to establish a lumen at this point. Cases have also been reported in which supernumerary lacrimal puncta and lacrimal ducts were present (Weber and others). There are at times small buds arising,‘ from the lacrimal-duct anlages, and in all probability these at times continue to develop independently until they reach and gain coalescence with the eyelids. The lumina for these super-numerary laerimal ducts are, of course, established just as they are in the regular ducts. 14 J. PARSONS SCHAEFFER

By the beginning of the third month (in some cases before) the lacrimal-duct cords have developed sufficiently to come in contact with the epithelium on the free borders of the eyelids. VVe will, however, find that the ducts are as yet in places solid cords. Portions of the mother cord, especially the portion that is destined to become a portion of the lacrimal sac, are active in lumen formation at this time. The fundus of the lacrimal sac apparently develops as a sprout from the mother cord. The nasal end of the mother cord has not developed sufficiently to come in contact with the mucous membrane of the inferior nasal meatus. It is, however, not far removed, and in a laterstage embryo it will be found coalesced with the nasal mucous membrane. Lumen formation at the point of coalescence of the mother cord with the nasal mucous membrane is delayed approximately until ‘term’ (figs. 22, 23 and 24).

Frontal sections of embryos aged approximately one hundred days will show that the nasal end of the mother cord of cells has developed to the nasal mucous membrane and has coalesced with it. Both laerimal—duct cords have grown to the free borders of the eyelids and have coalesced with the epithelium at these points. The mother cord of cells, or the portion destined to become the greater portions of the laerimal sac and the nasolacrimal duct, has by this time established irregular lumina at various points. The latter are best developed at the ocular end of the primary cord and towards the nasal end of the Cord. The lacrimal—duct cords have also established lumina at various points, especially in the regions of the knees, or what will later become the ampullae of the laerimal ducts.

In figs. 14, 15 and 16 (embryo aged one hundred and seven days) is well illustrated the irregular manner in which the cords of epi Figs. 14, 15, and 16 Photomierographs of frontal sections through the nascIaerirnal passages of a human embryo aged one hundred and seven days. Note both laerimal duets (fig. 14) in contact and fused with the epidermis in the region of the free borders of the eyelids. The laerimal ducts have not yet established lurnina in the regions of the eyelids (fig. 14). The remaining portions of the ducts are more orless patent throughout. Note the irregularity of lumen formation in the nasolaerimal duet (fig. 16). std = superior laerimal duct; 1'ld= inferiorlaerimalduet; cld = common laerirnal duet; ls = laerimal sac; nld = nasolacrimal duct. X 10.5. GENESIS OF NASOLACRIMAL PASSAGES IN MAN 15 16 J. PARSONS SCHAEFFER

thelial cells establish lumina. Note that the lacrimal ducts are more or less patent throughout, save at the free borders of the eyelids where solid cords still persist. The horizontal and vertical portions of the lacrimal ducts are well shown (fig. 14). The lacrimal sac (fig. 15) is well advanced but the remainder of the nasolaerimal duct is not wholly patent. Even at this early stage there is some evidence of beginning diverticula from the .nasolacrimal duct (fig. 16). The connection with the inferior nasal meatus is, of course, not yet established (fig. 16).

According to my studies, the ocular end of the mother cord is the first to establish a lumen. The horizontal portions of the lacrimal ducts become patent before the vertical portions (figs. 14 and 17). The last parts of the vertical portions of the lacrimal ducts to become patent are the junction points between the laerimal-duct cords and the epithelium of the free borders of the eyelids (fig. 17). The nasal end of the mother cord establishes a lumen before the middle portion of the cord (figs. 19 and 20). The middle portion remains solid, according to my series of embryos, for some time longer (fig. 19). The last portion of the nasolacrimal passages to become patent is at the point of coalescence between the nasal sprout of the mother cord and the nasal mucous membrane. This is usually deferred, as stated before, until ‘term’ or even later (fig. 24).

In the adult we find varying positions on the lateral wall of the inferior nasal meatus for the ostium of the nasolacrimal duct. The ostium also varies as to shape, and it is occasionally duplicated. Rarely we find a triplicity of the ostium.

The position of the ostium, i.e., whether at the highest point of the inferior nasal meatus, or at varying distances below the above point on the lateral nasal wall, depends, of course, largely upon the original point of coalescence of the mother cord of cells with the nasal mucous membrane (fig. 28). At times the area of coalescence between the cord of cells and the nasal mucous membrane is rather extensive (fig. 21). In such cases, due to the irregular mode of lumen formation, two or more ostia may readily b.e formed (instead of the usual single ostium) with a bridge of intervening tissue remaining permanently. The different shapes 49] "0

s

Figs. 17-21 Photomicrographs of frontal zseutions thmugh the nz-Lsn1acri1na.l passages of a human embryo aged one hundred and twenty days. Note the solid portions of the lat:rin1al ducts in fig. 17. In fig. 18 we mwo a patent section (ls) of the ocular end of the nasol-rm-,1'ima1 duct, and in fig. 19 a section of the mid—portion of the nasolacrimal duct, still solid (nld). Note the well established lumen (nlrl) at the nasal end of the nasolacrimal duct in figs. 20 .~m(l 21. Note how extensive the cont-actpoint between the nasolacrimal duct and the inferior nasal meatus will be (fig. 21). sld = superior lacrimal duct; ild = inferior l3.crirn:-11 duct; ls = lacrimal sac; nlcl = nas()lac1'i111al duct; Mr: = inferior Ixusal concha; i'rz.m = inferior nasal meatus. X 19.

THE .Am}-‘.nIc,\.\' JOURNAL OF ANATOMY, VOL. 13, No. l

17 18 J. PARSONS SCHAEFFER

Figs. 22-27 Photomicrographs of sections through the naso1a.c1'ima.l duct.

Fig. 22 From a. term child. Note that the connection between the na.solacrimal duct and the inferior nasal meatus is not yet established. "X 3.4.

Fig. 23 From a seven-month fetus. The connection between the nasolacrimal duct and the inferior nasal meatus is not established. X 6.1.

Fig. 24 From a term child. Barrier between the i'iasolacrima.l duct and the inferior nasal mcatus still present. Note the irregularity of the nasolacrimal duct. Compare with fig. 30. X 2.9.

Fig. 25 From an adult aged sixty years. Note the circular and regular condition of the nasolaerirhal duct. Reconstruction seen in fig. 29. X 2.6.

Fig. 26 From an adult aged sixty-five years. Note the marked diverticulum (X) from the nasolacrimal duct. The nasolacrimal passages of this individual are seen in reconstruction in figs. 30 and 31. X 2.6.

Fig. 27 From an adult aged seventy years. In the region of the ostium of the common lam-imal duct. X 2.8.

Fig. 28 1’hotographs of transections of tho nasolacrimal duet at the point of entrance (ostium of nasolao1'ima.l duct) into the inferior nasal meatus. Note

the different typos of ostia. (0). The sections are from adults and are magnified from two to four times.

lag. 29

years. and 31.


I{.acon.=Jt1'uction 01' L110 nasolacrimal passages of an adult aged sixty Note the regularity of the nasolacrimal duct. and compare with figs. 30 X 3.2.


Figs. 30 and 31 Reconstruction of the nasolacrirnal passages of an adult aged sixty-five years. Fig. 30 represents a medial View and fig. 3] a lateral View of the reconstruction. Especially note the irregularity, clue to divorticula, of the nasclacrimal duct. The portions illdicated in black at the inferior extremity of the nasolacrimal duct is a portion of the inferior nasal meatus. X 3.2. 22

of the ostia are doubtless due to the angle at which the original cord of cells meets the nasal mucous membrane. The position of contact also makes a difference. If the ostium is at the highest point of the inferior meatus, i.e., just caudal to the attachment of the inferior nasal concha to the lateral nasal wall, the opening of the nasolacrimal duct is usually a large, wide, open—mouthed ostium, unguarded by folds of mucous membrane (fig. 28). If, on the other hand, the ostium is farther caudal 011 the lateral Wall it is usually slit—like and more or less guarded by folds of mucous membrane (figs. 28).


Even at term the embryo presents very irregular nasolac— rimal ducts (fig. 24). After birth the Walls of the ducts become more and more regular. In the adult we very frequently find large divertieula from the nasolacrimal duct, and these added to other irregularities give us at times extremely irregular lumina (figs. 30 and 31). On the other hand we find adult ducts in which the lumina are very simple and regular (fig. 29). The lumina of the adult laerimal ducts (lachrymal canaliculi) are generally more or less irregular.

Summary

  1. The strand of thickened epithelium—the anlage of the naso— laerimal passages along the floor of the rudimentary naso-optic fissure becomes entirely separated from the surface, and for some time is wholly surrounded by mesenchymal tissue.
  2. The strand or cord of epithelial cells thus isolated from the surface is for some time Without a lumen.
  3. From the mother cord of cells both laerimal ducts and the nasal end of the nasolacrimal duet grow as sprouts. The cephalic portion of the laerimal sac also grows as a sprout from the mother cord.
  4. Considerable variation occurs in the development of the lacrimal ducts, i.e., as to number, time, and degree of development.
  5. The lumina of the several portions of the nasolacrimal passages are established in an irregular manner. The ocular end of the mother cord is the first to establish a lumen. The point of coalescence between the nasal end of the cord and the mucous membrane of the inferior nasal meatus is the last to become patent —the lumen here is established approximately at ‘term’ or even later. The horizontal portions of the lacrimal ducts establish lumina before the Vertical portions.


Wish to take this opportunity for expressing grateful acknowledgment to Professors Gage and Kerr for the material placed at my disposal in this investigation and for other courtesies extended. I am also indebted to Professor Ferris for reading the manuscript.

Bibliography

AsK, FRITZ 1907 Tiber die Entwickclung der Caruncula lacrimalis beim Menschen, nebst Bemcrkungen uber die Entwickelung der Tiiinenrorchen und der Meibomschen Drfisen. Anatom. Anz., Bd. 30.

V. BAER, KARL EnxsT1828—1837 TiberEntwiokelungschichte der'1‘hiere, Konigsberg.

BORN, G. 1876 Uber die Nasenhohlen und den Thr£i.nennasengang der Amphibien. Morphol. Jahrbuch, Bd. 2.

1879 Die Nasenhfihlen und (ler '.l‘l11'anennasengang dcr amnioten Wirbelthiere. Morphol. Jahrbuch, Bd. 5.

1883 Die Nasenhohlen und der Thranennasengang der amnioten Wirbelthierc. Morphol. Jahrbuch, Bd. 8.

BURDACH, KARL G. 1837 Die Physiologie als Erfahrungswissenschaft. Leipzig.

COSMETTATOS, F. 1898 Recherehes sur le développemcnt des Voies lacrymales. Thésc de Cloctorat. Paris.

COSTE, JEA.\r J. 1847-1859 Historic générale ct particuliere du développement des corps orgninsés. Paris.

EMMERT, E. 1876 Angeborenes Fehlen aller 4 Thréinenpunkte und Thra'nenrorehen. Archiv. f. A11gen- und Ohrcnheilk, Bd. 5.

ERDL 1845 Die Entwickelnng des Menschen und des Hiihnchens im Ei. Leipzig.

EWETZKY, TH. 1879 Beitrage znr Entwickelungsgeschichte des Auges. Arch. f. Augenheilk., Bd. 8.

1888 Zur Entwickolungsgeschichte des Thranennasenganges beim Menschen. Arehiv. f. Opth-al., Bd. 34, Ab. 1.

FLEISHER, B. 1906 Die Entwicklung der Thranenrorchen bei den Séiugetieren. Archiv. f. ()ptl1al., Bd. 62, H. 3. 24: J. PARSONS SCHAEFFER

HAMMAR, J. AUG. 1902 Studicn fiber die Entwicklung des Vorderdarms und einigcr angrenzcnden Organe. Archiv. f. mikroskop. Anat. und Ent— wick1ungsch., Bd. 59.

JOUVES, A. 1897 Recherches sur Ie développcrnent des voies lacrynialcs chez 1’e1nbryon de moutyon et 1"cxnbryon humain. Thésn de doctorat.

Toulouse.

K6LLIK1«;R, A. 1879 Entwickluxigsgeschichto dcs Mcnstthen und der hbhern Tiero. Leipzig.

1884 Grundriss dcr Entwicklungsgeschichte des Menschen und der h«")hern Tiere. Leipzig.

LEGAL, E. 1883 Die Nasenhiihlcn und der ’1‘}1r§Lnennasengang der amnioten Wirbelthiere. Morphol. Jahrbuch, Bd. 8.

LANG, PAVL 1911 Z111‘ Entwickelung dos Thriinenausfiihrappamtes bcim Menschen. Anat. Anz., Bd. 38.

KIAGNIIS, H. 1880 Mzmgel der unLeren Thrémenpiinlctc und Wfizrzchen auf beiden Augerl. Centralbl. f. prakt. Augenhcilk.

MATYS, 1905-1096 Die Entwickelung der Trfmnenableitungswege. Zeitsch. f. Augenhcilk, Bd., 14 u. 16.

SCHAEFFER, J. PARSONS 1911 The lateral wall of the cavum nasi in man, with especial reference to the various developmental stages. Annals of Otol. Rhinol. and Largyno1., June.

1911 Variations in the an-atoniy of the nzLso—1a.chrym2L1 passages. Annals of Surgery, August.

STANCULEANU, G. 1900 Recherches sur Ie développement des voies IB.(‘f1‘y!I12lieS chez Yhomxne et chez les animaux. Archiv d’0phtalm., Tom. 20.

WEBER, A. 1861 Optvhahnologischo Nliscellen und Aphorismen, 11 Zwci Féille Von i';berz£i.h1ig(:n Canaliculi lacrylnales. Archiv f.Op1:hahn010gie, Bd. 8, Ab. 1.


Cite this page: Hill, M.A. (2024, April 20) Embryology Paper - The genesis and development of the nasolacrimal passages in man. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Paper_-_The_genesis_and_development_of_the_nasolacrimal_passages_in_man

What Links Here?
© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G