Paper - A study of the causes underlying the origin of human monsters 15
|Embryology - 15 Apr 2021 Expand to Translate|
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Mall FP. A study of the causes underlying the origin of human monsters. (1908) J Morphol. 19: 3-368.
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A Study Of The Causes Underlying The Origin Of Human Monsters
Embryos of the Third Week
The specimens of the third week can be divided into three groups, representing normal embryos 16, 18 and 20 days old, respectively. In the ﬁrst division there is but one specimen, No. 166, and in it the dissociation of the tissues is complete.
|No. 12||2.1||18x 18x8||41|
|His (E)||2.1||8.5 x 5.5|
|His (Lg)||2.15||15 x 12.5||40|
|His(SR)||2.2||9 x 8|
|His (L)||2.4||9 x 8|
|Thomson||2.5||15 x 10||14|
|No. 318||2.5||20 x 18 x 11||42|
|Chiaringi||2.6||15 x 12 x 8|
|His (M)||2.6||8 x 7.5|
|Graf Spee||2.69||15 x 14||42|
|No. 239||3||19 x 17 x 15||50|
|His (BB)||3.2||14 x 11||48|
|No. 164||3.5||17 x 17 x 10|
|No. 186||3.5||25 x 20 x 15||17|
|No. 98||4||24 x 16 x 9||42|
|No. 136||4||14 x 11 x 6||56|
|His (III)||4||30 x 25||51|
|No. 148||4.3||17 x 14 x 10||38|
|No. 76||4.5||22 x 20|
|No. 248||4.5||30 x 23 x 15|
|No.||Embryo||Chorion||Menstrual Age||Changes in the Chorion|
|166||2.3||40 x 40 x 40||71||Tubal pregnancy.|
|115||3||30 x 27 x 22||56||Atrophic.|
|196||3||12 X 12||56||Atrophic Tubal pregnancy.|
|209||3||25 x 15 x 10||Atrophic.|
|246||3||30 x 21 x 14||Hyaline.|
|292a||3.5||50 x 30 x 30||54||Fibrous.|
|324||3.5||45 x 45 x 22||Fibrous and atrophic.|
|189||4||28 x 25 x 15|
|228||4||60 x 25 x 25||79||Very fibrous.|
|244||4||25 X I5 X 15|
|253||4||38 x 30 x 15||Hyaline.|
|302||4||25 x 20 x 15||Fibrous.|
|309||4||23 X 20 x 20|
|399||4||4 or 5 Wks|
|402||4||40 x 25 x 20||6 or 8 Wks|
|328||4.5||Normal and covered with necrotic syncytium.|
This is not remarkable, for the menstrual history says that it is 71 days old, showing that the pathological process has been under way at least a month. The ovum has thick walls with a large cavity within lined entirely by the amnion, which is not attached to it at any point. There are no blood-vessels in the villi of the chorion. The embryo is cylindrical in form and is attached for half its length to the amnion and then perforates it. Its organs and tissues are almost completely dissociated, there being but the faintest outline of the nervous system in its center. In the tail end of the embryo there is a blind tube, which may represent the allantois. Within a sac on one side of the body, which communicates with the cmlom, there is a small mass representing either the heart or the umbilical vesicle. Greater changes could not have taken place without obliterating the anatomy of the specimen entirely. There are eight specimens (Nos. I15 to 400) of the second group in this series, that is, embryos which began to degenerate when they were 18 days old. A variety of changes are found in each specimen which are by no means of the same degree, thus permitting their discussion in regular order. It is probable that those with the least amount of change in them have been under pathological inﬂuences for less time than in those in which the tissue changes are more marked.
There are practically no changes in embryo No. 209, and for this reason it may be classed with normal specimens. However, it appears as if the chorion were atrophic, being very thin immediately over the embryo, and the amount of magma reticulé within the coelom is greatly increased. There are some changes in the amnion, as it has become adherent to the embryo over its tail and back, and is wanting entirely over its head. There are numerous cells in the surrounding magma which may have migrated from the meso— derm. It is clear that in this specimen the primary trouble is in the chorion immediately over the embryo, which receives most of its blood—vessels at this stage. The amnion and coelom were next affected, and had the abortion not followed the tissues and organs would soon have dissociated.
The dissociation of the tissues is well under way in embryo No. 246, the chorion of which is somewhat hyaline and the amnion greatly distended. Unfortunately, the embryo is broken. Enough of it remains, however, to show that the central nervous system is distended and partly ﬁlled with round cells, which seem to be derived from the dissociated neural tube. The heart and large blood—vessels are empty, and the liver and optic vesicles are wanting.
The changes in this specimen can be ascribed to the hyaline chorion, but it is difﬁcult to understand how this can cause distention of the amnion and destruction of the umbilical cord. At any rate, the process of dissociation is well illustrated in this embryo. The sharp boundaries of the tissues and organs are obliterated and the cells which are liberated take on an indifferent form. With the dissociation of the walls of the bloodvessels the blood corpuscles wander out, to be added to the dissociated tissues, and convert the whole into an indifferent mass, which barely outlines the embryo. Such a condition is found in No. 196. The tissues are nearly homogeneous, only the central nervous system and some of the large bloodvessels being recognizable on account of the increased number of nuclei in these regions.
In No. 115 the amnion is greatly distended and the embryo is spread out upon it, much as is the case in the chick in normal development. The body cavities communicate freely with the coelom, VVolfﬁan bodies are still visible, and the central nervous system, heart and some large blood-vessels are represented as bands of round cells.
Various degrees of dissociation of the organs are seen in difterent embryos, as is naturally to be expected. In No. 292a, for instance, the outline of the body cavity is very marked, it being distended and partly filled with round cells. The amnion is also greatly distended, ﬁlling the entire coelom. There is no umbilical cord. Some of the spinal cord is still sharply outlined; otherwise the dissociation is complete.
In embryo No. 252 the dissociation is complete with the exception of the eyes, which have been converted into small black spots composed of pigment cells. The skin is also markedly thickened, the epidermis forming papillomata, as well as small lens-like bodies.
In the specimens just considered only those organs which are present in the early part of the third week were seen, there being no signs of cartilage, muscles nor peripheral nerves. In the next group of ten specimens we have clearly the remains of organs and forms of embryos to correspond with normal ones of the latter part of the third week, that is, embryos 4 and 4.5 mm. long.
This group can also be arranged in the order of the degree of pathological change. In No. 189 the central nervous system is open below throughout its whole extent. A number of motor nerve roots are developed, more in the region of the tail than elsewhere. There are no cranial nerves present. The heart is almost detached from the body, and the large blood-vessels are irregular in shape and changed entirely from the normal type. The liver, stomach and intestine are wanting entirely, and the dissociation of the optic vesicle, chorda, allantois is almost complete. In this embryo the branchial arches and brain show the least changes in them, while the rest of the tissues have suffered most.
Specimens Nos. 302, 309 and 328 are in many respects alike and may be considered together. The walls of the brain and cord are much folded and ﬁll the central cavity in No. 302, while in the other two they are thin, the central cavity being enlarged and well ﬁlled with round cells, which, however, do not all seem to arise from the walls of the nerve tube, for their nuclei are smaller, being similar to those of blood cells.
The tissues of these embryos are pretty well dissociated, being composed largely of round cells, within which the outlines of large blood-vessels may be seen. No. 328 has arms and legs attached, which have undergone mucoid degeneration, a well marked cavity, pleuro-peritoneal, and ﬁnally remnants of precartilages which are not fully dissociated.
In the next embryo (No. 228) the central nervous system has also shown itself most resistant. It is markedly dilated and the walls are partly dissociated. There are also small links of cells present, which remind one very much of the growing cord, connecting large masses of dissociated tissue. The ventricle is dilated and has within it a large mass of dissociated nerve cells. In the face there are two large nerve tubes extending from the brain, which no doubt represent the eye vesicles and their stalks. The embryo with epidermis intact, connects with the degenerated but apparently active umbilical vesicle, but not with the chorion. The vascular system is represented by a dissociated heart and a large bloodvessel, which extends into the umbilical cord. The rest of the tissue is a dissociated mass, more or less spotted, being composed of a variety of cells, including possibly remnants of myotomes.
Degeneration of the dissociated structures now follows rapidly. In No. 253 the embryo still shows the outlines of the pleuro-peritoneal cavity within, but the tissues have become more hyaline, the round cells having diminished in number. Most of the central nervous system is fully destroyed. There are traces left of some of the large bloodvessels, the Wolfﬁan ducts and the chorda dorsalis. No. 244 may be considered together with this specimen, for in it radical changes have also taken place. The central nervous system is still sharply deﬁned, more so in the brain than in the spinal cord. The heart is represented as a mass of cells in front of the head. Below this there is an irregular body, probably the dissociated liver, composed of epithelial-like cells intermixed with some round cells. The rest of the tissues are of homogeneous structure, with an occasional necrotic mass. In the tail end of the embryo there are some blood spaces with blood corpuscles, some of which inﬁltrate the surrounding tissues. In many respects this specimen resembles No. II 5, with the difference that it is larger and was probably a little older when the pathological process began in it.