NODULAR CYEMATA. 77 



implies that such cyemata had once reached a higher stage of development, and 

 that they then underwent retrogressive changes. However, this does not neces- 

 sarily imply that the tissues composing the different organs have migrated out 

 actively, mingling with each other after the manner of cells in tissue cultures. 

 In the case of dissociation, as implied above, the disorganization of the cyema has 

 been a passive rather than an active process, occurring during and being incidental 

 to the process of maceration and disintegration. When the dissociation is at all 

 marked, sections of specimens, when examined microscopically, are rather uniform 

 cytologically. 



The decidua was included in only 23, or 37.1 per cent, of the specimens belong- 

 ing in this group, and infiltrated in all of these; 69.5 per cent were listed as marked 

 infiltrations and 31.5 per cent as mild. Although these percentages are practically 

 the same as in the preceding group, the infiltration is milder. In the former group 

 severe infections predominated and abscess formation was relatively common. 

 In this group, on the contrary, the infection, as judged by the character of the 

 infiltration present in the decidua, was milder in all save a few cases which plainly 

 suggest mechanical interference with the gestation. This may be one reason why 

 the cyemata, though rudimentary, nevertheless are present. All of the cases of 

 infection, except these, could, I believe, be designated quite correctly by the term 

 chronic endometritis. I came to this conclusion largely from a study and com- 

 parison of those specimens in which the presence of a chronic endometritis had 

 been diagnosed clinically. Indeed, it is quite inconceivable that such an inhibition 

 of normal growth as existed in the nodular embryos could possibly occur in the 

 presence of a sudden severe infection. The latter could destroy only portions of a 

 normally developed cyema, for it would quickly die. 



The homocytic nature of some of these specimens also impressed Giacomini 

 (1888), who spoke of a lymphoid transformation of the embryo. In 1894 Gia- 

 comini also spoke of a "uniformity of the elements which are like lymphoid cells 

 so that one might think at sight that one dealt with a lymph follicle. " Giacomini 

 found this lymphoid transformation both local and general and stated that the 

 elements which composed the organs in a case observed by him were transformed 

 into round cells. However, he did not regard this transformation as wholly 

 passive, for he, like His, believed in post-mortem cell proliferation. While empha- 

 sizing that a microscopic examination is indispensable for an understanding 

 of abortive forms of embryos, His (1891) added that we are not far wrong if we 

 speak of certain small accumulations of pycnotic cells found in abortive forms as 

 a "Brut von Wanderzellen. " Although His described dissociated specimens and 

 regarded an invasion of abortive forms by round cells as undoubted, he neverthe- 

 less stated that, although not all cells may be dead, one can not regard abortive 

 forms of embryos as living. 



In later years Mall used the term dissociation in another sense, and appar- 

 ently also felt that more or less independent and continued development might 

 take place after the death of the embryo, much after the fashion of a tissue cul- 

 ture in vitro. 



