THE TESTICLE AND THE OVARY 



375 



and 620). The changes were not excited by the presence of ova in 

 the uterus, since they took place when the lower part of that organ 

 was ligatured off so as to prevent the passage of the ova. On the 

 other hand, if the ovaries were extirpated deciduomata could not be 

 produced. If the corpora lutea were as far as possible burnt out 

 of the ovaries by the electric cautery, deciduomata were not generally 



FIG. 97. Experimentally produced placenta of pseudo-pregnant rabbit ; section 

 of uterus showing connective tissue forming decidual cells which enclose 

 vessels. (From Hammond:) 



produced ; but owing to the difficulty of properly performing these 

 experiments, the results were not quite conclusive. Lastly, when 

 pieces of uterus were transplanted into the subcutaneous tissue, 

 deciduomata were formed in the grafted pieces. It is concluded, 

 therefore, that the ovaries at certain periods after ovulation (and 

 probably the corpora lutea) elaborate a predisposing substance in the 

 presence of which indifferent stimuli (traumatisms) may produce 

 deciduomata. Hammond has obtained similar results with rabbits. 1 



1 Hammond, loc. cit. 



