49° Diseases of the Genitai ' Orga?is 



a healthy cow, the infection passes through the body of the 

 healthy cow "in bond" and fatally attacks the intra-uterine 

 young, thus passing through an intermediary organism 

 without injury, to attack fatally a third individual. 



In irreconcilable conflict with such belief, the group of 

 veterinarians to which I belong hold that the observed ex- 

 pulsion of a fetal cadaver is a phenomenon devoid of great 

 mystery — that fetal death is fundamentally like extra-uter- 

 ine death and occurs in a perfectly analogous way. Not 

 only is fetal death analogous to post-natal death, but, with a 

 single limitation, death in the two eras is due to identical 

 causes. The limitation — and it is a highly important one — 

 is that many of the important infections of post-natal life 

 are unable to attain contact with the fetus. The uterine seal 

 serves as an effective barrier against invasion through the 

 genital tract, and the placental filter, when healthy, is not 

 known to permit the passage of any organism competent to 

 cause disease. No such passage of disease-causing organism 

 through the healthy placenta to the fetus has yet been re- 

 corded. Even the ultra-minute disease-producers which 

 defy the finest filter made by man, such as the virus of hog 

 cholera, smallpox, and many others, do not destroy the life 

 of the fetus directly, but only indirectly by destroying the 

 life of the pregnant female. 



I have held that the infections causing the phenomenon of 

 abortion are far less mysterious than generally claimed and 

 are in all respects analogous to, and in an important degree 

 identical with, the infections of extra-uterine life. Every 

 part of the genital tract of both sexes and of all ages com- 

 monly harbors bacteria of great variety. Under ordinary 

 conditions these may not cause evident disease, but under 

 the numerous and vital changes of function in the genital 

 tract, they may and do acquire power to cause vital injury. 

 The uteri of most non-pregnant and pregnant cows and heif- 

 ers contain bacteria having pathogenic powers. The epi- 

 didymis and vesiculae seminales of bulla often contain bac- 

 teria which cause definite lesions in these parts. Under 

 certain conditions such bacteria are ejaculated with the 



