3 PREFACE. 



regarding these matters seems quite insufficient to enable one to formulate satis- 

 factory hypotheses regarding many of the phenomena encountered in abortuses. 

 To enable us to do this a much better localization and identification of the 

 enzymes concerned would seem to be necessary. 



That the dissolution of these early embryos, and undoubtedly also of the 

 chorionic vesicles, is not due primarily or even very materially to phagocytic 

 activity, is very evident, even upon cursory examination. In the presence of the 

 intact chorionic and amniotic vesicles such a process is wholly excluded. Besides, 

 one never sees any evidence of phagocytosis of the preserved fetal by the maternal 

 tissues in human conceptuses, although evidences of the contrary processes are 

 not wanting. 



In considering some of the many problems of human antenatal pathology, 

 it seems very probable that much light can be thrown upon them by comparative 

 experimental pathology and studies in comparative gestation. A reliable knowledge 

 of the comparative incidence of abnormalities in man and higher vertebrates 

 alone would be of great value. The same thing would be true of a knowledge of the 

 comparative incidence of uterine and ovarian or testicular disease and abnormali- 

 ties of the uterine mucosa. Indeed, until these and other similar and related 

 questions have received at least a partial answer, it will always remain rather 

 venturesome to draw final conclusions regarding many things in human antenatal 

 pathology, for the first question that always must be answered in connection with 

 a particular specimen is that of its normality or pathogenicity. 



His, Giacomini, and Mall took up this problem with especial devotion and 

 have done much to lay the basis for the accomplishment of the task set for path- 

 ologic embryology by MUller (1847). Miiller stated that it was the task of the 

 pathological anatomy of prenatal life to show the progressive steps leading from 

 the slightest deviation from the normal to the most pronounced deformity. This 

 task is only begun and progress naturally will be slow, especially in connection 

 with early forms, until we can discriminate better between the normal and the 

 abnormal and the pathologic. 



A comparison of the clinical data relating to infection, with the microscopic 

 findings, will show that the correspondence is extremely slight. This is not sur- 

 prising, for physicians themselves often emphasize that the history probably is 

 quite untrustworthy. Moreover, the clinical diagnosis of infection is usually 

 based upon the presence of fever, a putrid discharge, or certain symptoms usually 

 regarded as indicative of fever. If the clinical reports regarding infection were 

 based upon bacteriologic or even upon histologic examination, they would un- 

 doubtedly agree better with our findings. These showed the presence of infection, 

 as indicated by infiltration of the decidua or by abscess formation, in a large 

 percentage of the cases in which the decidua was present, in the specimens falling 

 into the first five groups. 



The unavoidable confusion resulting from the use of the word ovum to desig- 

 nate the unfertilized female sex-cell, this cell when fertilized, the chorionic and 

 amniotic vesicles with or without the embryo, and even the later product of con- 



