88 STUDIES ON PATHOLOGIC OVA. 



approximately the correct age for an embryo of 4.5 mm. long, 127 days is entirely too 

 old for one with a length of 20 mm. Specimens of approximately the same alleged 

 menstrual age are found to differ widely in length, and fetuses of approximately 

 the same length may differ greatly in menstrual age. Nor can these discrepancies 

 be attributed to the unreliable character of the menstrual histories, for specimens 

 with identical menstrual ages often vary considerably in size. This is illustrated 

 splendidly in cases of double-ovum twins. In one of these instances (No. 1840) 

 the fetuses have a length of 15.9 and 38.5 mm. The larger of these twins is 

 normal in every respect and macerated but slightly, but the smaller is greatly 

 macerated and stunted. Since both these specimens are of identical age, they 

 illustrate how misleading even a reliable menstrual history may be. 



In a second case, that of No. 788 a, b, one is a nodular cyema described under 

 group 4 and the other a stunted specimen included in this group. The organs of 

 the latter or larger fetus, though dissociated, are all well outlined, and the vertebral 

 disks especially well defined, in spite of the fact that it must have been dead a 

 considerable period of time. The umbilical vessels are degenerate and the limbs 

 atrophic. The menstrual history unfortunately is not known, or it would be pos- 

 sible to make some conjecture at least as to the probable length of retention in 

 utero after fetal death. However, if we assume that the large fetus is smaller than 

 it should be, as undoubtedly is the case, and take its anatomical age to be that of 

 a length of 20 mm., it would have a normal menstrual age of about 7 weeks. The 

 small nodule (7886), which was only 2 mm. long, does not show a development 

 corresponding to that of a normal specimen of this length, and on the basis of 

 size would have an age of less than one month. This, however, does not necessarily 

 imply that it died at that time. Indeed, the relative preservation of the tissues 

 of the two fetuses makes this very unlikely, although we must remember that such 

 a small nodule as 7886 could probably be preserved for a long time in such a large 

 quantity of sterile amniotic fluid as that in which it was contained. 



Another instance which shows the misleading character of the menstrual 

 histories, even when known, is that of No. 1914, a case in which a large mass of 

 hydatiform cysts accompanied a normal, living fetus of 7 months. A still better 

 illustration is the case of Slemons (1917 a ), in which a nodular mass, apparently a 

 twin, accompanied a normal viable fetus. Since it is not improbable that such 

 specimens as some of these have been taken to establish the occurrence of super- 

 fetation, they will be mentioned in a later chapter. 



In the other three cases of twins included in this group the cyemata fall into 

 the same instead of into different groups. In two instances (Nos. 207 a, b, and 

 341 a, 6) this may be due to the fact that they are single-ovum twins, even if they 

 are not of the same size. In the third case (No. 330 a, b), although from double 

 ova, both fetuses were of the same length. The appearance of these conceptuses 

 indicates that they were retained for a considerable period after fetal death, and 

 the history confirms this. Syphilis was suspected in this case and bleeding began 

 six weeks before the abortion occurred. Furthermore, the sizes of these fetuses, as 

 well as the condition of the tissues themselves, clearly indicate that both had 

 probably been dead some time before hemorrhage began. 



