94 



THE PHYSIOLOGY OF REPRODUCTION 



the bitch's uterus, describes the inucosa as growing to three or 

 four times its normal thickness, but this observation has not been 

 confirmed. The growth is accompanied by enlargement and conges- 

 tion of the capillaries, which at the same time become more 

 numerous. 1 The vessels in the surrounding muscular tissue also 

 tend to enlarge. The epithelium undergoes no material change so 

 far as seen. In the case of the ferret the uterine cavity is described 

 as becoming markedly reduced in size, while the glands are stated 



polym. 



x, bl. 



FIG. 14. Section through proiestrous uterine mucosa of dog. (From 

 Marshall and Jolly.) 



ex. bl., Extravasated blood corpuscles ; polym., polymorph ; sec., cells 

 probably indicating secretory activity. 



to undergo an appreciable swelling accompanied by an increased 

 secretory activity. 



(3) Period of Destruction. The walls of the stretched blood-vessels 

 break down, and red corpuscles, accompanied by leucocytes, become 

 extravasated throughout the stroma. Some of the vessels, however, 

 remain intact. The breaking down of vessels appears to occur fairly 

 uniformly throughout the stroma instead of being restricted to any 

 particular portion. The extravasated blood for the most part collects 

 immediately below the superficial epithelium, but it is not aggregated 

 in large lacuna-like spaces, such as Heape has described in the monkey. 



1 Cf. Retterer, loc. cit. ; also KeifFer, " La Formation Glandulaire de 

 1'Uterus," Annales de la Soc. Medico-Chirurg. de Brabant, 1899 ; and Bonnet, 

 "Beitrage zur Embryologie des Hundes," Anat. Hefte, vol. xx., 1902. 



