ORIGIN OF THE CORPUS LUTEUM 



155 



marked in extent. Sobotta ('96), reviewing the evidence, is 

 inclined to the last view. Pfluger ('63), in an experimental 

 investigation, found that in cats and rabbits killed violently 

 there was much more frequent bleeding into young corpora 

 lutea than in animals killed without struggle and very carefully 

 autopsied. In my own specimens, out of sixteen sows whose 

 ovaries contained very early corpora lutea, dressed at a packing- 

 house using the relatively gentle method of scraping by hand, 

 four showed more or less blood in the corpora lutea and twelve 



Fig. 13 Cells from theca interna of recently ruptured follicle (sow in heat, 

 ova in tubes). Iron haematoxylin stain, showing pigment and broken-down 

 erythrocytes in theca cells. X 1000. 



were entirely free of macroscopic haemorrhage. In another 

 establishment, where the carcasses are conveyed 150 feet dang- 

 ling from a chain and are scraped by engine-driven revolving 

 vanes (so that in the bodies of pregnant sows, young foetuses 

 frequently suffer an effusion of blood into the amniotic sac), 

 there chanced to be a somewhat higher proportion of haemor- 

 rhagic follicles; but even there, in spite of such excessive vio- 

 lence, it is common enough to see delicate corpora lutea one or 

 two days old come through with no blood at all in their cavi 



