On Abortion in Cows. 



77 



of perfection in the male and female, that sexual connection fails 

 to ensure any further advance ; nature can do no more, and there 

 must be limits somewhere. In relation with the system of high 

 breeding we must remember that various collateral circumstances 

 are to be considered, which materially influence the constitution 

 of the male and pregnant female. These animals, for instance, 

 are mostly highly fed from birth, are carefully and warmly 

 housed, and have every attention bestowed which can favour their 

 rapid and perfect maturity ; they are descended from ancestry 

 which for generations has been equally well attended to, and which 

 was all excellent stock in its day; in fact, they have, as it were, 

 been gradually approaching limits beyond which art cannot fur- 

 ther command the resources of nature. If, however, cows such 

 as just named are put to an inferior or comparatively ill-bred 

 bull, they will for the most part conceive, and the perfect male 

 animal will beget stock in cows much his inferior in blood,'* 

 Wild animals very rarely abort or fail to conceive ; not having 

 been subjected to the modifying influences which artificial inter- 

 ference entails, they maintain a uniform standard consistent 

 with those capabilities of propagation which have never been 

 forced beyond the natural or original conditions of their consti- 

 tution. 



A cow (andespecially a young one) which has cast her calf once, 

 is very likely to do the same again, and usually at about the same 

 period of gestation. To such an extent does this liability exist, 

 that some animals abort for many times successively, and even 

 without any apparent cause beyond that which, to a common ob- 

 server, appears to depend on habit. In the human female this 

 periodical or repeated abortion is also very usual, and most diffi- 

 cult to overcome. It seems owing to a peculiar disposition in the 

 uterus to evacuate its contents, when, in consequence of their de- 

 velopment, they have produced an amount of distension beyond 

 which the organ containing them has been unaccustomed to 

 extend. Thus it is that cows having carried several calves to the 

 full period of gestation, although afterwards subjected to abortion, 

 are less liable to become habituated thereto than are young 

 animals which cast their first calves. In the latter case the 

 uterus never has expanded to its full capability, and at a second 

 pregnancy is disposed to empty itself at about the same period, 

 and under the same amount of stimulus as it did before. 



III. Causes luhich, influencing the si/stem or a part of it, act 

 through it on the uterus. — In many parts of the country a belief 

 exists that abortion is contagious. From extensive observation 

 and inquiry, we find this opinion founded on the fact, that when 

 abortion once commences in a herd of cows, it frequently affects 

 them in considerable numbers. Whilst we must remember that 



