HYDATIFORM DEGENERATION IN TUBAL AND UTERINE PREGNANCY. 335 



with 66.6 days in 51 uterine specimens. Moreover, 32 of the 48 tubal specimens 

 of hydatiform degeneration, or 66.6 per cent, fall into the first two groups, thus 

 again showing that the majority are small, young specimens. 



Although the incidence of hydatiform degeneration among the pathologic 

 tubal specimens is but slightly higher than that among the pathologic uterine 

 specimens, the incidence of hydatiform degeneration in all tubal specimens con- 

 tained among both the normal and pathologic is twice as high as that among the 

 same classes of uterine specimens. This can be explained only partly by the fact 

 that a larger proportion of the tubal specimens are young and pathologic. The 

 pathologic tubal specimens form 69.2 per cent of 153 normal and pathologic tubal 

 specimens found among the first 1,187 accessions, but the pathologic uterine 

 specimens form only 33.6 per cent of the normal and pathologic uterine groups 

 among the same accessions. But the real question remains, for the incidence of 

 hydatiform degeneration among the specimens classed as pathologic was essentially 

 the same in tube and uterus. Hence an increased incidence of 100 per cent in hydati- 

 form degeneration in the tubes may be due to the less favorable nidus found there. 

 If so, it throws a very significant light upon the probable cause of hydatiform 

 degeneration, which would seem to lie in the conditions surrounding the implanta- 

 tion and early development rather than in the ova or spermatozoa themselves. 



The conclusion reached in a study of uterine specimens that hydatiform 

 degeneration is absolutely less, not more frequent near the menopause, is confirmed 

 also by the study of the tubal specimens. The average age of 20 women in the 

 tubal series was 33.9 years, as opposed to an average of 31 years obtained from 36 

 women in the uterine group. This age difference offers a tempting opportunity 

 for generalization, and did the statistics include thousands of cases one might be 

 willing to say that it points to a progressive change as cause, which begins in the 

 uterus and finally reaches the tubes. But strangely enough, the average number of 

 years of married life of 15 women in the tubal series is exactly the same as that of 

 29 women in the uterine series, or 7.1 years. This fact at once guards against a 

 venturesome hypothesis, for it allows no longer period for the supposed ascending 

 change to reach the tubes than the uterus. 



Eight of 20 women from the tubal series had borne one child, 4 had borne two, 

 and 3 more than two; thus again more than confirming the statistical findings in 

 the uterine series, which show that 9 of 33 women had borne once and 18 but twice. 

 The parallelism between these statistics is striking indeed, especially if the small 

 numbers be considered; 14 of 23 women, or 60.8 per cent, in the tubal series had 

 aborted but once, as compared to 19 out of 44, or 46.3 per cent in the uterine series, 

 a fact which again points to the middle rather than to the end of the reproductive 

 life of these women. 



I do not know whether or not hydatiform degeneration in the tube also is 

 relatively more common near the menopause, as will be shown to be the case in the 

 uterus, for I have not been able to obtain data on the relative frequency of tubal 

 pregnancy in the different decades in the reproductive life of women. However, 

 since by far the greater number of pregnancies usually occur early in this period, it 



