NODULAR CYEMATA. 79 



are found in these specimens. However, it is necessary to bear in mind that such 

 errors in development as are here described need not necessarily be the product 

 of the environment in which the conceptus finds itself, but may in fact be changes 

 or abnormalities which resulted from defects inherent in the spermatozoa, in the 

 unfertilized ovum, or in the fertilized ovum even. However, in order not to 

 interrupt the description of this group, a consideration of this question is post- 

 poned until all the groups have been considered. 



Although the nodular embryos themselves are so very abnormal in form and 

 structure, there was very little indeed in the outward form and gross appearance 

 of the corresponding chorionic vesicles to prompt special comment at the time 

 of the first description. Sometimes it was noted that the villi were unusually 

 long and thread-like, or that they were absent over considerable areas; but nothing 

 else attracted attention as a rule. Some of the chorionic vesicles are translucent, 

 but this is true also of many in other groups. Upon closer examination, however, 

 the presence of numerous "appendicidurate" can be determined in many specimens, 

 and upon magnification of about 1 1 diameters with the binocular it was found that 

 a very surprising number of chorionic vesicles included in this group showed the 

 presence of a very marked and wholly typical hydatiform degeneration of the 

 villi. In many instances the appearance of these villi is an exceptionally artistic 

 one. The characteristic vesicles can be seen in all degrees of development, even 

 when they were too small to have attracted attention upon inspection of the 

 gross specimen with the unaided eye. Indeed, it was not until my attention was 

 directed especially to the possible meaning of certain forms of degeneration so 

 frequently seen and usually referred to as "hyaline" or "mucoid" in the protocols, 

 that the relationship between the two was established. These degenerations, and 

 especially the absence of vessels in most of the specimens examined, had also 

 attracted my attention earlier in the year, while engaged with a study of Hofbauer 

 cells in abortuses. 



Under microscopic examination it was found that the most constant and 

 interesting change in the stroma of the villi in this group of nodular cyemata is 

 the occurrence of hydatiform degeneration which is present in 29 per cent, includ- 

 ing two doubtful cases. In order not to confuse matters, it is necessary to add 

 that the term is being used in its literal meaning, entirely aside from any clini- 

 cal implications. As a rule, the stroma of these villi tends to become clear or is 

 clear, or is even replaced completely by a clear fluid. This change is usually 

 designated as a hyaline or mucoid degeneration in the protocols, and sometimes 

 also as fibrous degeneration. As emphasized by Mall, the use of the word "mu- 

 coid" does not imply that the material is mucous, although Mall noticed that it 

 frequently stains blue with hematoxylin. As is well known, however, true mucin 

 nevertheless has been found in small amounts in the fluid contained in the vesicles 

 of hydatiform moles. 



In the early stages of hydatiform degeneration the stroma of the villi may 

 still contain remnants of blood-vessels, but usuaUy these are completely absent. 

 In these or somewhat later stages the nuclei are pycnotic and may be quite well 



