THE TESTICLE AND THE OVARY 



375 



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

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

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

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

 produced. If the corpora lutea were as fai' as possible buiiit out 

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



s^ 



m « 



\ 







Fi(i. i)7. — Experimentally produced placenta of pseudo-pregnant rabbit ; section 

 of uteru.s showing connective tissue forming decidual cells which enclose 

 vessels. (From Hammond.) 



produced; Imt owing to the ditticulty of properly performing these 

 experiments, the restdts 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 o\'aries at certain ])eriods after ovulation (and 

 prol)ably the corpora lutea) elal«n'ate a predisposing substance in the 

 presence of which indifferent stinndi (traumatisms) may produce 

 deciduomata. Hammond has oljtained similar results with rabbits.^ 



Hammond, lor. at, 



