CHANGES IN NON-PREGNANT UTERUS 105 



edges of the adjoining epithelium which had not suffered destruction. 

 In this way the re-formation of the epithelium is sufficiently 

 accounted for, since, as already remarked, only a very inconsiderable 

 number of cells is removed during the sheep's prooestrum. 



Congestion of the stroma gradually diminishes, and the mucosa 

 as a whole undergoes a slight shrinkage. It would appear that a 

 few new capillaries are formed, but there is no evidence that any 

 of the extravasated corpuscles are gathered up afresh into the 

 circulatory system. On the other hand, there are ample indications 



pig. 





Fig. 22. — Section through portion of uterine mucosa of sheep, showing black 

 pigment {pig.) formed from extravasated blood. 



that all those corpuscles which remain in the tissue become trans- 

 formed into pigment, as originally concluded by Bonnet.^ According 

 to this investigator, the extravasation takes place in the deeper 

 mucosa, and the derivatives of the corpuscles are carried in the 

 form of pigment to the more superficial area by wandering cells. 

 Kazzander,^ however, does not admit the agency of leucocytes ; but 

 the most recent observations support Bonnet's conclusions, excepting 

 that (as previously stated) the extravasation which takes place 

 during the destruction period is in the superficial mucosa rather 



' Bonnet, " Ueber Melanose der Uterinschleimhaut, etc.," Deutsche Zeitsch. 

 f. Tkiermedizm, vol. v., 1880, and vol. vii., 1882 ; " Beitrage zum Embryologie 

 der Wiederkauer, etc.," Arch. f. Anat. u. Phys., Anat. Abth., 1884. 



^ Kazzander, loc. cit. 



4 A 



