HUMAN MAGMA RKTICULK IN NORMAL AND I'ATIK tl.(H IICAL DEVELOPMENT. 23 



l^ometimcs the entire specimen is filled with a gelatinous mass, which becomes 

 firmer when fixed in formalin and separates into a more solid mass, and into a licjuid 

 when preserved in formalin. This mass appears to lie within the amnion in most 

 specimens, as in cases where it fills the whole ovum the amnion is missing. Speci- 

 men No. 604 (plate 1, figures 1 and 2) is quite typical, as is also Xo. 135. In both the 

 embrj'os are atrophic and necrotic, and the jelly-like fluid fell out with ease when 

 the ovum was cut open. The chorion is atrophic in both of them and is covered 

 only with a few atrophic villi. Specimen No. 604 came to mc without a history, 

 and measures 70 by 50 by 50 mm. It is full}- covered with fibrinous clots, between 

 which there are few large villi, as the picture shows. The chorionic wall is 3 to 4 

 mm. in thickness, and its interior is entirely filled with jelly-like magma of uniform 

 consistency. On one side of the specimen, lying free within the hyaline magma, 

 is a straight embryo, 17 nnn. in length, with atrophic head, arms, and legs. The 

 same descrij^tion aj^plics eciually well to No. 135. Specimens like these are ciuite 

 numerous in our collection of human ova, but usualh' the jelly is lost when the speci- 

 men is opened. Figures illustrating embryos of this sort may be seen in my pai:)er 

 on monsters, under the description of embryos Nos. 79, 94, 230, 261, and 270. 



No. 1117 (plate 1, figure 5) contains an embryo well packed in the jelly-like 

 magma. The cavity of the ovum is small and its wall is xevy hemorrhagic. The 

 specimen came from a woman, age 26 3'ears, who was married at 15. She had two 

 births at term and one i)revious abortion. She believed she became pregnant 

 about 3 months before the operation, although she had not missed her regular 

 periods. 



Another specimen belonging to this category is No. 813. It consists of a fleshy 

 mole, well filled with tough, jelly-like magma. All the villi are destroyed and its 

 surface shows ulceration. Further study of this magma is necessary before it can 

 be related to the granular magma which forms with the reticular magma in the 

 exocoelom. I am inclined to t)elieve that the hyaline substance which is so often 

 found within the amnion of pathological specimens arises from the amniotic liquid, 

 which has become richer in albumen, and therefore congeals into a jelly-like mass 

 when preserved in formalin. 



CONCLUSION. 



The fibrils forming reticular magma are always in direct continuity with those of 

 the mesenchyme of the chorionic wall. This can easily be demonstrated by means 

 of Van Gieson stain, and reticular magma must therefore be viewed as embrj'onic 

 connective tissue extending into the cavity of the ovum. The stronger strands are 

 accompanied more or less by mesenchyme nuclei, showing that the magma itself must 

 be viewed as independent connective tissue identical with the mesenchyme of the 

 chorion. As the amnion extends these strands are pushed aside, their final remnants 

 being seen in that portion of the exocoelom which encircles the umbilical cord. 



In pathological specimens the reticular magma increases in quantity in the earlier 

 stages of development, continuing for a number of months of pregnancy. Fre- 

 (luently the meshes between the reticular fibrils are filled with peculiar stratified 

 granules which take on an extensive hematoxylin stain. Often the amnion is 



