HUMAN MAGMA RETICULE IN NORMAL AND PATHOLOGICAL DEVELOPMENT. 19 



cut into sections before it was received at the laboratory, with the statement that 

 no embryo had been found, it having fallen out. I found that the half sent con- 

 tained a ccelom. 3 by 2.5 mm., filled with magma, in which there was a cavity about 

 1.5 bj' 1 mm. Sections showed that the cavitj' was natural and not sharply defined, 

 with nothing to indicate that it had contained an embryo. On the contrary, it 

 was found that the magma reticule was composed of a loose network of mesoderm 

 cells, which bound one side of the chorion with the other. These cells are directly 

 continuous with those of the mesoderm and resemble them in every particular. 

 At one ]ioint there is a small group of epithelial cells, which may represent what was 

 originally the embryo. Otherwise, the chorion and its villi are normal in appear- 

 ance, being encapsulated in decidua which has in it some uterine glands. All in 

 all, this specimen reminds one very much of the Peters ovum. There are some leuco- 

 cytes in the decidua, but no accumulation of them indicating inflammation of the 

 uterus. l~^everal figures, illustrating this specimen, may be found in my monograph 

 on monsters. 



Specimen No. 531 is in many respects similar to the one just described (No. 278) . 

 It came from a Avoman who had been pregnant 6 times, her j^eriods having been 17 

 days overdue before this abortion. The ovum is spherical, 19 mm. in diameter, and 

 is covered only by a mass of \illi, which appear normal. The ccelom within con- 

 tains many magma fibrils, the meshes of which are more or less filled with dense 

 granules, as is shown in plate 1, figure 8. Within this mass there is a detached 

 vesicle, 1.5 mm. in diameter, which no doubt represents the umbilical vesicle. 



A specimen intermediate between the two just described is No. 250, of which 

 several illustrations are published in my paper on monsters. The specimen came 

 embedded in a mass of decidua and was obtained by scraping the uterus. When 

 opened it was found filled with magma reticule just beneath the chorion, in which 

 could be seen a small embryo, and farther away towards the center of the coclom 

 was the umliilical vesicle. The whole ovum was cut into sections. The chorion 

 and the Ailli are apparently normal in shape and structure, being also rich in blood- 

 vessels, which are filled with embryo blood. The villi are bathed in mother's 

 l>lood and covered with an active trophoblast. The decidua is somewhat infil- 

 trated with leucocytes, but there are no abscesses. The front end of the amnion is 

 absent, and its free edge and the embryo are embedded in reticular magma, indicat- 

 ing that the amnion was destroyed before the abortion took i^lace. The general 

 shape of the embryo and its degree of development are practically' normal. The 

 heart is well formed and, including the blood-vessels, is filled with blood. The ali- 

 mentary canal, brain, spinal cord, otic and eye vesicles, myotomes, and branchial 

 arches are much like those of embryo No. 12, to be described presently. The 

 septum transversum is well marked and the th3Toid gland is just beginning. The 

 tissues of the embryo, however, and the cavity of the front end of the brain are 

 filled with numerous small round cells with fragmented nuclei. All stages of frag- 

 mentation are seen, just as may be observed in the leucocytes in small abscesses. 

 Most of the red blood-cells are within the blood-vessels, l)ut those within the ti.ssues 

 appear perfectly normal. On account of the diminished number of mesoderm 

 cells, which, in fact, diminish in pro])ortion as the fragnienled cells increa.se, the con- 



