Changes in Generative- Organs, etc., of Non-Pregnant Dog. 553 



mammary tissue was chiefly represented by ducts in the neighbourhood of 

 the nipple. 



It is necessary to assume that the uterine glands undergo considerable 

 increase in size and number with the approach of the pro-cestrum, for at 

 this period they are well represented and lined by a columnar epithelium 

 (fig- I)- 



The changes which occur in the cestrous cycle of the Dog were first briefly 

 described by Eetterer, whose account was afterwards amplified and to a 

 great extent confirmed by Marshall and Jolly. The postoestrous changes , 

 however (excepting for the first few days after " heat "), were not recorded, 

 it being supposed that the uterus rapidly resumed the resting condition. 

 The postoestrous glandular hyperplasia was first described by Keller, who 

 has supplied a very careful account of the changes in the uterus from the 

 pro-cestrum onwards until rest. This investigator obtained a series of stages 

 until the eleventh week by removing portions of the uterine wall from living 

 bitches at varying intervals and then allowing the cycle to continue. In 

 this way he procured a succession of stages showing the growth and increase 

 in the glands and the subsequent retrogressive changes, the occurrence of 

 which is confirmed in the present paper. Keller's records* obtained in the 

 way described, were supplemented from some further material obtained 

 promiscuously. Keller gives an account of the changes undergone by the 

 epithelium of the crypts and glands, and records the existence of a secretion 

 within their lumina during the " ruckbildung " or retrogressive stage. 

 Certain of Keller's stages, however, were taken at somewhat long intervals, 

 and this may account for his having missed altogether the extravasation 

 stage represented in Case 7. The paper is written with especial reference to 

 the existence of endometritis in the human uterus. The part played by the 

 corpus luteum in relation to the changes and their physiological significance 

 are not considered, and there is no record of the synchronous processes 

 undergone by the mammary tissue. 



The changes in the uterine glands and stroma tissue of the pseudo- 

 pregnant dog are in a general way very similar to those of the marsupial 

 as described by Hill and O'Donoghue. These authors point out that the 

 processes which occur in the pseudo-pregnant marsupial are essentially 

 identical with those which take place in the pregnant animal. A similar 

 statement can be made about the Dog, as is shown by comparing Duval's 

 description and figures of the uterine mucosa at different stages of pregnancy. 

 The extent of the glandular development (the object of which is to help to 

 provide nourishment from the secretion produced for the growing embryos 



