a'STJ.-CM. 61 



the immediate result is the distending and erection of the bulb of the ovary. 

 This modification in the ovarian circulation extends to tlie uterus, so 

 that both are in a state analogous to erection ; the prolonged tension is 

 communicated to the vessels and capillaries of the mucous niemhranc ; 

 the epithelium is shed, leaving the tunic of the capillaries exposed, and 

 this soon gives way, whence results the haemorrhage, which })crsists as 

 long as the erection and obstruction to the free How of blood tln-ou"li 

 the veins continues. This is the case in the human female, but it nmst 

 be admitted that, in several animals, the erectile formations are either 

 in a rudimentary condition or entirely absent. 



In the Bitch the bulb of the ovary is moderately developed ; but the 

 arteries of the uterus, although contorted in a spiral form, are not such 

 avascular mass of vessels as to constitute a real erectile organ. In 

 Ruminants, small vascular masses or formations are observed near the 

 cotyledons, which may be taken to represent the spongy texture of the 

 human uterus. 



That the menstrual flow is independent of the influence of the ovaries, 

 and even nearly all of the uterus and its ajjpendages, would appear to 

 be established by several important facts connected with the subject of 

 ovariotomy or "spaying." There is a tradition among those who 

 practise this operation on Sows, Bitches and Cats more particularly, 

 that it does not prevent their showing signs of oestrum unless they are 

 operated upon when pregnant ; this is more especially the case with 

 animals which have already produced young, but it is nevertheless the case 

 also sometimes with young animals which have never been bred from.' 



With regard to the season at which this " heat" takes place, it has 

 been observed that it is usually the spring-time, when food becomes 

 plentiful, especially with Herbivorous animals. The Carnivora are in 

 heat during winter. The Mare is usually in heat from April to June, or 

 later. \Vith the Cow whose Calf is sold at from one to two months old, 

 with a view to utilising the milk, the season of course is varied, as care 

 is taken to induce conception again as soon as the lacteal secretion 

 begins to diminish ; but it has been observed that midsunnner is more 

 particularly the rutting period. And the " heat '' in Sheep, though 

 naturally present in September, is usually only shown during summer, 

 because the Ewes are kept apart from the Ram at the natural time, in 

 order that the Lambs may be born at a favourable season — the spring ; 

 and the period of suckling over (four or five weeks), they may be weaned 

 when the herbage is tender and nutritious. .\nd in other circum- 

 stances, particularly with animals bred for tlie butcher, tlie rut is 

 induced sooner by putting the Ewes in contact with the Kam at an 

 earlier period, so as to obtain two or three lambings in the year. 



The Bitch is in heat from December to February, or in the autumn 

 and spring-time. 



' A strikinjf in.ttance of this h.oa been given recently by Barthelniy, in tlie Journal dc. 

 Medeciii'' I'etcrinaire, who a.-<.serta that the (pstnim or " nit '' can occur in Piijs after com- 

 plete removal of the ovaries. A professional spayer operated on thirty-ei^jht young Pigi 

 under sixty days old, yet these animals showed the symptoms of " rtit " at from three to 

 eight months, and monthly after that a^e, as thou^;h they had not l)een spayed. .\n action 

 was brought against him, after M. liarthelmy had given his opinion that the a-strum 

 indicated incomplete removal of the ovaries. The defendant declared that he had seen 

 ivstnim in pigs which had l>een properly si)aytd. The court ordered that five of the 

 Figs which showed all the phenomeii.'t of rrstruin to the greatest extent, shouM be killed 

 and examined by a competent veterin.iry surgeon. This was done, and it w.-vs found that 

 in each case the operation had been well performed — the ovaries, tubes, and almost the 

 entire cornua of the uterus having been removed. 



