224 STUDIES ON PATHOLOGIC OVA. 



strual age, usually is present. This stands in contradiction to the earlier belief 

 illustrated by the statement of Gierse (1847), that the fetus usually was reported 

 as absent, and that when present (as in the cases of Meckel, Gregorini, Otto, 

 Cruveilhier, and his own) it was usually less than an inch long, even when retained 

 for a period of from 3 to 10 months. 



This apparent contradiction regarding the presence of the fetus in hydatiform 

 moles is explained easily by the fact that the cases in the earlier literature are old, 

 far advanced in degeneration, while the more recent literature contains many more 

 in the earlier stages of degeneration. Yet in spite of this fact the earlier opinion 

 survives to the present day, for Graves (1909-10) spoke of "the very unusual 

 presence of a normal fetus inside a mole," and Vineberg (1911) still more strangely 

 held that the presence of a fetus excludes the specimen from the class of true hydati- 

 form moles! 



Among the specimens concerned in this report many contained a fetus. This 

 was true of 24.5 per cent of 49 tubal and 64.4 per cent of 121 uterine specim'ens, 

 including some (9) doubtful cases. The fetal length ranges from 1 to 90 mm. in 

 the uterine and from 1 to 80 mm. in the tubal series. Although the average length 

 of the embryo in the tubal series is 12.3 mm., and that of the uterine only 10.1 mm., 

 58 per cent of the tubal specimens nevertheless were below 7 mm. in length as con- 

 trasted with 52.5 per cent of the uterine. The presence of a fetus with a frequency 

 almost three times as great in the uterine series again indicates that the abnormal 

 conditions within the tubes lead to early death, digestion, and absorption, or at 

 least to dissolution, of the embryo. This fact again points directly to a faulty 

 nidus as causative agent, for if the absence of a fetus is to be laid to primary ovular 

 defects, then one must admit that relatively far more of such diseased ova become 

 implanted within the tube than within the uterus. 



In some early specimens the fetus is in a state of excellent preservation. This 

 is what one might expect, for the onset of hydatiform degeneration is gradual and 

 may remain partial. The condition of the fetus alone in many of them also suggests 

 that its death was secondary to the degeneration. 



This is exemplified splendidly by No. 2099, shown in figures 129 and 130. 

 This cyema shows the presence of undoubted maceration changes throughout, 

 but especially in the branchial region and on the umbilical cord, and the shaggy 

 chorionic vesicle shows the presence of a moderate degree of hydatiform degenera- 

 tion. A more advanced instance is that of No. 1260, shown in figures 131, 132, and 

 133, in which the form of the cyema is greatly modified and the hydatiform nature 

 of the villi much more obvious. That the death of the embryo is not the cause of 

 hydatiform degeneration would seem to be evident also from such instances as 

 No. 2250. In this case of twin pregnancy both fetuses are well preserved, as figure 

 134 shows, and yet the respective chorionic vesicles show the presence of well- 

 developed and quite general hydatiform degeneration as can be seen in figures 141 

 and 142 (plate 14, Chap. X). Indeed, in this instance the fetuses show less 

 maceration change than the vesicles, and it is particularly interesting that this 



