Talk:Paper - The embryonic development of the ovary and testis of the mammals
2. Material and Technique
The material employed includes numerous stages in the development of the ovary and testis of the rabbit, from the 13-day embryo to and including adult stages. The pig material includes only embryonic stages, but is more complete for the period covered than is the rabbit material.
The two forms studied - rabbit and pig - are complementary in their points of special suitability for this work. Although there are minor differences in the development of the sex glands in these two forms, yet the general process is essentially the same. In general the pig is the more instructive form for a study of the early stages of embryonic development, while the rabbit furnishes material better suited for the study of the post-embryonic stages.
The following tables indicate the stages studied, the sex of the specimen and the number of series cut in each case. The stage of development is indicated in the rabbit by the number of days and in the pig by the length of the embryo.
Rabbit.
f 13 D.
14KD.
16 D.
17 D. ! 18 D.
19 D. 21 D. 23 D. 25 D. {2& D.
At Birth.
Indifferent. 1
Female. Male.
3 2 2 2 4 2
f 3D.
8 D.
10 D.
13 D. .. 1
17 D. .. 1
24 D.
25 D. .. 1 31 D. .. 1
m -{ 37 D. .. 1
45 D . . . 1
50 D . . . 1
78 D. .. 1
85 D. .. 2
93 D. .. 1
100 D. .. 1
130 D. .. 1 1
[ 140 D . . . . . 1
One each of the following stages of adult rabbit ovaries ; 6-months-old virgin. Old individual, 3 months since last
pregnancy. 3K da.ys pregnant.
s^2
7 13
14K
16
17
During lactation.
1st pregnancy.
Stages. 0.6 â– cm. 0.7 cm. 0.8 cm. 0.9 cm. 1 cm. 1. 1 cm. 1.25 cm. 1.33 cm.
1.4 cm.
1.5 cm.
Pig Embryos
Indifferent.
1
1
1
1
1
1
1
1
4
Female. Male.
1.6
1.7
1.8
2.5
3
3.5
4
5
5.7
7.5
8
8.5
10
13
13.5
15
18
20
cm. cm. cm. cm. cm. cm. cm. cm. cm. cm. cm. cm. cm. cm. cm. cm. cm. cm . cm.
Note The pig embryos were measured from the cervical to the tail bend in all stages up to 5 cm. length, when the measurement was taken from the base of the tail to the top of the head. This change was made for practical reasons of precision. The 5 cm. stage would be about equivalent to the 4 cm. stage.
The material Avas, in practically all cases, fixed in Flemming's fluid and stained with Heidenhain's iron hematoxylin with a counter stain of Siiurefuchsin, Orange G. or Bordeaux red. Sections were cut to a thickness of 6f /j or in a few cases 10 /u and were mounted in series. It was, of course, necessary in all cases to section the anterior part of the mesonephros together with the sex gland itself.
An account of the earlier literature upon this subject would be useless repetition, since we have such valuable and extensive reviews as those given by Waldeyer, 70 and 02, Born, 94, Coert, 98, Winiwarter, 00, Bouin, 00, Mihalkovics, 85. In the general summary reference will be made to some of the more recent and important works bearing upon these problems; but no attempt will be made to attain completeness in a consideration of the earlier literature, a very large part of which is of merely historical value.
