10 HUMAN MAGMA RfiTICULfi IN NORMAL AND PATHOLOGICAL DEVELOPMENT. 



with Grosser's figure of the Peters ovum, it becomes clear that the two spaces in the 

 latter are in reality the beginning of the exoccelom. 



The studies referred to al)ove indicate that the space near the emliryo is the 

 primitive e.\oca?lom and that the remainder of the so-called ca^•ity of tlie chorion is 

 simply the young normal ovum filled with delicate fibrils which communicate freely 

 with the fibrils of the chorionic membrane. We have in our collection a young 

 normal specimen, No. 763, containing an embryo anlage 0.2 mm. in length, which in 

 general confirms the observations in the Peters ovum. A list of th(> normal speci- 

 mens in our collection discussed in this i)aper is given in table 1. 



Table \.— List of normal embryos. 



Specimen No. 763 was removed from a woman who was the mother of 6 children, 

 the oldest being 10 years old. She had had one miscarriage. During the year 

 before the operation she suffered much from headache and backache, but otherwise 

 her health appeared to be normal. When she was admitted to the hospital she com- 

 plained of abdominal enlargement and there was some urinary disturbance. At 

 the operation for rupture of the perineum the uterus was scraped out; subsccjuently 

 the ovum was found in one of these scrapings. The fragments both of the mucous 

 membrane and ovum appear to be normal. 



Unfortunately we have only a few of the sections of this valuable specimen, but 

 these show that we are undoubtedlj' dealing with a normal ovum of the same stage 

 of development as that described by Peters. The chorionic cavity is partly filled 

 with mother's blood, but there are some strands of reticular magma, with nuclei and 

 protoplasm radiating through the blood. The specimen has been stained in hema- 

 toxylin and eosin, which is not especiallj' favorable for defining magma fibrils. 



The specimen described by Herzog is also luidoubtedly normal, as it was 

 obtained from a woman who was killed b}^ a stab-wound through the heart. The 

 large colored plate published by Herzog shows the specimen to be quite identical 

 with that of Peters. It shows free cells in the ca^lom, which contains no other for- 

 eign substance, but a jjhotograjjh (figure 24, published by Herzog) shows that the 

 ccelom is filled bj' a very jjronounced substance, reminding one ver}' much of reticu- 

 lar magma. The same is true of a specimen recently described by Johnstone. A 

 colored photograph which he published shows quite distinctly a pronounced magma 

 throughout the ccelom. (See, for instance, his figure 3.) This establishes definitely 

 the presence of reticular magma in ova the size of the specimen of Peters. We have, 

 however, the valuable specimen of Brj^ce and Teacher, which also shows the condi- 



