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OBSTE TRIG A L PHYSIOL OG V. 



toms of " heat " persist for some time after this act, and the erethism of 

 the generative organs is not allayed, although in reality impregnation has 

 taken place; and in very exceptional instances the "heat " will return 

 after having disappeared for a certain time. Some Mares pregnant for 

 two or three months, and especially those which have been put to the 

 stallion early in the year, ^'111 exhibit indications of oestrum when the 

 weather becomes warmer and the pastures afford more nutriment. When 

 in this state the female may again receive the male, and it may even hap- 

 pen that a second fecundation takes place at this time ; thus occasioning 

 those somewhat unusual conceptions which give rise to superfoetation — 

 though if pregnancy is somewhat advanced, it is dangerous and may 

 occasion abortion. A story is told of a Mare in the Saint-Leger stud, 

 France, which, after being pregnant for some months, yet showed symp- 

 toms of " heat." Louis XIV., who was more inclined to favor the de- 

 sires of the animal than to listen to the opinion of Garsault, the famous 

 equestrian of that period, ordered her to be put to the stallion. This 

 was done, copulation took place, and the Mare aborted. 



Stallions exclusively employed for covering, frequently refuse to 

 approach pregnant Mares in which the " heat " persists or reappears ; 

 though this is not always the case, particularly with young stallions. 



In the Cow, as in the Mare, oestrum may continue or reappear after 

 fecundation ; though as a rule, I believe, the male refuses to copulate 

 again when the female is in this condjj;ion. " Very often," says Grognier, 

 " the Mare and Sheep, as well as the Cow, manifest signs of ' heat ;' but 

 the Bull, better than the Stallion or Ram, knows the indications of gesta- 

 tion, and abstains from having intercourse while they are in this state." 

 M. Magne remarks that the Bull accustomed to consort with pregnant 

 Cows, smells at them as it does at others going with it, but without being 

 excited by their emanations. Exceptionally, however, it must be noted 

 that Cows have been known to manifest oestrum regularly, and to receive 

 the Bull, even a month before parturition. But these instances are very 

 rare. For cattle, therefore, it is an almost certain sign of pregnancy 

 when the Bull refuses a Cow, though the latter may be in heat. 



With Sheep oestrum may continue after fecundation, and the Ram may 

 copulate. 



In general terms, then, it may be said that the cessation of oestrum 

 before its regular period, and soon after copulation, indicates that con- 

 ception has taken place : that its persistence or reappearance in the Mare 

 and Sheep some time after the first copulation, does not absolutely imply 

 that impregnation has not occurred, even though the male again consorts ; 

 but if it frequently appears it is a presumption that the female is not only 

 not pregnant, but that fecundation is not readily induced. 



It has been generally observed that a change takes place in the char- 

 acter of the animal which has conceived, and this sometimes almost im- 

 mediately after conception ; the change being something analogous to 

 that produced after castration. Mares which were previously vicious, 

 troublesome, or unsteady when in " heat," are nearly always gentle and 

 tractable when in foal ; the genital excitement which caused their capri- 

 ciousness or viciousness being allayed, they are no longer under its in- 

 fluence. This change, when occurring after copulation, is a valuable sign 

 of successful impregnation ; and though it may sometimes fail, yet when 

 present, it can scarcely lead to a mistake. If, on the contrary, the animal 

 has not been fecundated after one or more coverings, its vices become 

 exaggerated when again put to the Horse. 



