Puerperal Diseases of the Uterus 567 



tached from the uterus. There exists then what may be 

 designated cervical retention of the fetal membranes. A 

 condition has developed analogous to retention of the fetal 

 cadaver. Unless surgically removed, the membranes then 

 undergo putrid destruction and establish pyometra or other 

 serious type of disease of indefinite duration. 



The biology of the infection causing retention of the fetal 

 membranes has not been adequately or seriously studied. 

 The orthodox believers in "contagious abortion" as a spe- 

 cific contagious disease have neither asserted, admitted, nor 

 denied that B. abortus causes retention of the fetal mem- 

 branes. They freely admit and assert that abortion is 

 "followed" or "complicated" by retention of the fetal envel- 

 opes. In their directions for the control of "contagious 

 abortion", however, they constructively deny the identity 

 of the infection causing abortion, and of that causing the 

 retained placenta of calving, by advising that aborters be 

 quarantined and ignoring the cow which has calved and has 

 retained fetal membranes. Brief researches by my col- 

 leagues intimate that the chief factor in the causation of 

 retained fetal membranes is a streptococcus of the viridans 

 group associated at times with a colon bacillus. The latter 

 may be largely a secondary invader. Very rarely tubercu- 

 losis and actinomycosis may cause retention of the fetal 

 membranes. Reference to this possibility has been made 

 when considering genital actinomycosis and tuberculosis. 

 Any infection which may invade or exist within the gravid 

 uterus and which is competent to cause inflammation may 

 cause retention of the fetal membranes. After the expul- 

 sion of the fetus, or rather after the uterine seal disappears 

 from the cervical canal, an unknown number of species of 

 bacteria may invade the uterus to complicate and intensify 

 retained placenta. 



The course of retained fetal membranes is ameliorated, 

 intensified or modified by innumerable factors, and it is im- 

 possible to predict the outcome of a given case with any as- 

 surance of correctness. The mortality is high, but the 

 greatest economic loss arises from decreased dairying effi- 



