132 OBSTETRICAL PHYSIOLOGY. 



hydrometra, ascites, etc. — may give rise to amplification of the abdomen ; 

 and it must not be forgotten that Mares fed on poor fibrous forage not 

 unfrequently have the belly enlarged. So that of itself this is not at all 

 a sure criterion of pregnancy. 



Taken in connection with the other signs, however, the increase in the 

 abdomen — most marked towards its inferior third, and becoming evident' 

 towards the fifth or six month of pregnancy — has a certain value. It is 

 most noticeable, perhaps, in looking at the animal from behind ; though 

 repeated examinations at various intervals may be necessary to ensure 

 certainty, and in important cases recourse may even be had to measure- 

 ment of the abdomen. 



The enlargement of the fnammce is a sign which varies considerably in 

 different species, according to the condition of the females. In primipar- 

 ous animals, as the Mare and Cow, they begin to increase soon after 

 conception — ^towards the second or third month. The udder is more 

 prominent and firm to the touch, loses its wrinkles, and the teats are 

 more visible. This appearance is generally only ephemeral and par- 

 tially disappears, to reappear again more markedly after some weeks ; 

 then to subside and show itself several times during the process of ges- 

 tation. 



Besides this mammary enlargement in the primiparae, and which may 

 be accepted as a certain indication, these glands furnish, towards the 

 last third of the period of gestation, a yellow, viscid, transparent liquid — 

 the colostrum — similar to white of e^g, and which can be easily extracted 

 from the teats by milking. In the last weeks of pregnancy this liquid 

 sometimes become white and opaque, as we.i as less viscid, and is then 

 milk. When the animals have bred several times, the increase in the 

 size of the udder is only remarked in the last days of gestation. In milch 

 Cows, and particularly in those which are not good " milkers," another 

 sign is to be found in the diminution of the lacteal secretion, and the 

 shrinking of the gland some time after conception — usually about the 

 twentieth day. 



In the pregnant Mare which still has a foal running with her, the se- 

 cretion of milk also ceases some time before parturition, and the animal 

 appears to be aware of this, for it weans the foal generally between the 

 sixth and eighth month. 



In the smaller animals, the enlargement of the mammae and the appear- 

 ance of the milk are usually remarked earlier, and more regularly, than 

 in the larger creatures. 



Though, in a natural state, the mammary glands are only intended to 

 furnish aliment to the young creature until it is sufficiently strong and 

 active to find its own food, when they suspend their function ; yet domes- 

 tication has greatly modified their secretory power in some species — as 

 with the Cow, Goat, and sometimes the Ass and Sheep — and the secretion 

 of milk becomes an almost permanent office. Not only this, but at times 

 the secretion, as observed in the unimpregnated Bitch, is very anomalous 

 and unnatural. In the non-pregnant female of various species — not 

 excepting the human species — the secretion may appear naturally or be 

 induced by mulsion or frequently repeated suction of the teats, even in 

 very young creatures, a short time afterbirth ; and what is more astonish- 

 ing, male animals have, in rare instances, assumed a function which 

 is alv/ays looked upon as specially characteristic of the female sex at the 

 maternal period. So early as the days of Aristotle — who mentions a he- 



