AJ5TATOMY AND HISTOLOGY OF THE OVARIES 549 



that it is quite distinct from the hyaline material described by other 

 authors. 



It is of course unsafe to say whether these remarkable conditions in 

 the bat have any close counterpart in the human species. Up to the present 

 time no progress has been made in the investigation of structural changes 

 in the corpus luteum induced experimentally. All our information is 

 based upon the doubtful action of extracts and the existence of a more or 

 less close association between seemingly parallel changes on the corpus 

 luteum and other tissues. 



