Changes in Generative Organs, etc., of Non-Pregnant Dog. 549 



and the point of rupture was clearly visible. In the cavities there were 

 many signs of recent haemorrhage, for red corpuscles and blood pigment 

 were abundant. The cells destined to contain lutein had already undergone 

 some hypertrophy, while connective-tissue cells and small blood-vessels had 

 grown inwards from the surrounding tissue. 



Sections through the uterus showed extravasated blood in considerable 

 quantity, lying, for the most part, a little below the surface epithelium 

 (cf. Marshall and Jolly, and Keller). There was no clear evidence of 

 destruction of epithelium having occurred, but the duration and extent of 

 external bleeding on the preceding days is proof of a considerable discharge 

 of blood having taken place from the mucosa into the lumen of the uterus. 

 The superficial epithelium was cubical ; that of the crypts opening directly 

 into the lumen of the uterus was more columnar and showed evidence of 

 mitosis. The glands situated in the deeper portion of the stroma were also 

 lined by a more or less columnar epithelium. They were slightly more 

 numerous than in the pro-oestrous stage (described by Marshall and Jolly, 

 and Keller), and their lumina were very widely open. The stroma was 

 denser than during the pro-cestrum. 



The mammary gland tissue was limited almost entirely to a few ducts in 

 the neighbourhood of the nipple, and there was no evidence of proliferation 

 taking place in such mammary tissue as was present. 



(2) A rough-haired Terrier (a virgin) began to show pro-oestrous bleeding 

 from the vaginal opening on May 21. Bleeding continued until June 2, 

 when it seemed to have stopped. Slight bleeding was, however, resumed 

 next day and continued until June 6, when it finally ceased. The bitch was 

 killed on June 10, when her organs were preserved. Each ovary contained 

 four organised corpora lutea, which may have been about a week old. The 

 prolonged continuance of slight bleeding from the vulva seemed to suggest 

 that in this case oestrus had commenced and ovulation taken place before 

 the discharge had quite ceased. Otherwise the pro-cestrum had been of 

 abnormal duration. The degree of development of the corpora lutea sup- 

 ported the first suggestion, for, excepting for the fact that the cavities were 

 not entirely filled in, these organs were fully formed. They occupied a large 

 part of the ovary, and were well vascularised. 



The sections through the uterus showed a slight increase in the number 

 of glands in the deeper portion of the stroma, as compared with the stage 

 described above. The epithelium lining the crypts and glands was throughout 

 columnar rather than cubical, the nuclei being situated in the basal portions 

 of the cells. The lumina of the glands were not so widely open as in the 

 preceding stage. The connective tissue was fairly dense, but somewhat 



VOL. LXXXIX. — B. 3 A 



