Changes in Generative Organs, etc., of Non-Pregnant Dog. 551 



(5) A Fox Terrier (a virgin) experienced pro-cestrous bleeding from 

 February 2 to February 9 and was killed on March 11, or 31 days after 

 bleeding ceased. Both ovaries appeared to be composed very largely of luteal 

 tissue. It was subsequently found that the right ovary contained two corpora 

 lutea and the left ovary three. Sections showed that the corpora lutea were 

 still well vascularised but beginning to undergo very slight retrogression. 

 The luteal cells were much hypertrophied but vacuoles were beginning to 

 appear in some parts of the tissue. 



The uterus also showed slight evidence of retrogressive changes having set 

 in. The crypts and glands were smaller. The epithelium lining them was 

 less often columnar and in places was almost or quite cubical. The gland 

 lumina frequently contained a colloidal substance, and in the case of some 

 glands there were appearances which suggested a recent desquamation of 

 epithelial cells. Vessels were abundant in the interglandular tissue, but the 

 capillary development was less noticeable than in the preceding stage. The 

 muscular walls, however, showed little or no evidence of having undergone 

 any change. 



The development of mammary tissue was more prominent than in the 

 preceding stage, and active proliferation was apparently still proceeding. 

 Large numbers of acini had been formed (figs. 5 and 7). No fat was present 

 in the intermammary tissue, but this was probably mainly a result of the 

 animal's condition. The tissue was not markedly vascular, but vessels could 

 be distinctly seen. 



(6) A Fox Terrier (multiparous) experienced pro-cestrous bleeding from 

 August 4 till August 14 and was killed on September 21, or 38 days later. 

 Superficial examination showed that the right ovary contained two corpora 

 lutea and the left ovary three. The ovaries unfortunately were not preserved, 

 so that it is not possible to describe the histology of the luteal tissue. 



Sections through the uterus presented several differences from those of the 

 preceding stage. The interglandular connective tissue constituted the greater 

 part of the area of the stroma, the glands being both fewer and smaller in 

 diameter. Small capillaries containing red corpuscles were numerous in the 

 stroma. The glands throughout were lined by cubical epithelium, the nuclei 

 being placed centrally and occupying about two-thirds of each cell as seen in 

 section. The gland lumina contained colloidal substance, and here and there 

 were portions of what were probably remains of epithelial cells (fig. 3). 



The bitch being multiparous, the mammary tissues were well developed 

 and consequently unsuitable for comparison with the stages described above. 

 No secretion or fluid oould be expressed from the nipples. 



(7) A long-haired Terrier (multiparous) experienced pro-cestrous bleeding 



3 a 2 



