Cystic Degeneration of the Corpus Luteum 415 



cysts which have their principal danger for the animal in 

 their mechanical interference with other viscera. Their 

 origin is unknown. It is not improbable that a considerable 

 proportion of them have their origin in the cystic degenera- 

 tion of the corpus luteum. 



The origin of the cystic corpus luteum has not been ex- 

 tensively studied. Judging from clinical and post-mortem 

 studies, it appears quite justifiable to say that the disease 

 is referable to an infection which enters the crater of the 

 freshly ruptured ovisac from the oviduct. Hence the cystic 

 corpus luteum is seen with great frequency in instances of 



3 3a 



6 7 8 



Fig. 132 — Cystic Corpora Lutea. 



/, 2, Twin corpora lutea of pregnane}' ; 3, ja, 



4, 5, cystic corpora lutea. 



chronic salpingitis. In fact a large percentage of cows and 

 heifers persistently sterile because of salpingitis suffer sim- 

 ultaneously from cystic degeneration of the corpus luteum. 

 When the ovary becomes adherent within the pavilion of the 

 tube, cystic degeneration of the corpus luteum is essentially 

 constant. 



The bacteriology of the cystic degeneration of the corpus 

 luteum has been but scantily studied. Thus far the studies 

 have revealed chiefly the presence of a streptococcus of the 

 viridans group. 



In many sterile animals, the cystic degeneration of the 

 corpus luteum advances somewhat rapidly, causing no ma- 

 terial enlargement of the corpus luteum but gradually de- 

 stroying the lutein tissue, until finally it no longer inhibits 



