80 



On Abortion in Cows. 



causes affections of the lungs, and food undue in amount or bad 

 in quality produces disease of the stomach and bowels. 



The uterus and ovaries of the young virgin female of any animal 

 are organs of comparatively small size, and not being concerned 

 in the performance of functions essentially necessary to the 

 vitality of the body, they receive but a small supply of blood and 

 nervous influence. At the adult period of life these organs, 

 having attained their full development, exercise upon the system 

 an influence of the most important kind. In the cow at periods 

 of cestrum they receive a greater amount of blood, and their 

 nervous susceptibility is greater than heretofore. If she be 

 allowed intercourse with the male, ccmception follows ; the pre- 

 sence of the foetus maintains a stimulus in the uterus which is 

 continued till the tim.e of parturition ; the quantity of blood de- 

 termined to it is enormous, and the peculiar kind of nervous 

 influence required to take cognizance of its functions progres- 

 sively increases as gestation advances. The gravid uterus then 

 is the seat of a healthy excitement, and the due preservation of 

 this depends partly on a comparatively quiescent state of the rest 

 of the system; hence the cow during pregnancy is more than 

 usually docile. Some persons are of opinion that the imagina- 

 tion of a pregnant animal is easily acted on by impressions which 

 at other times would scarcely produce any effect, and many cases 

 can be adduced which show that sudden fright and intense men- 

 tal emotion have been followed by abortion. 



When a pregnant cow, then, is so situated that she can smell 

 the odour arising from another cow which has aborted, we 

 may reasonably expect that the sensation so produced will, from 

 what has been stated, be attended with peculiar consequences. 

 The circle of nervous influence, which establishes a connection 

 between the organs of smell, the brain, and the uterus, will be 

 influenced thereby, and the uterus, from the predisposing nature 

 of its condition and functions, especially responds to this pecu- 

 liar stimulus. Irritation applied to nerves induces action in 

 organs to which such nerves pass, and, in the present insiance, 

 action, as a result of nervous excitement, is induced in the uterus, 

 which organ c(mtinues from time to time to act upon its contents 

 until they are expelled. Thus we conceive it is that odours arising 

 from cows casting calf induce abortion in others of their pregnant 

 companions, and by adopting this explanation we can account 

 for xhe apparently contagious nature of abortion, without admitting 

 that it is contagious in reality. Other odours of an offensive 

 kind are believed by some (and we think, with good reason) to 

 cause abortion. Cattle will often collect in numbers around 

 places containing decomposing animal and vegetable matter, and 

 by bellowing, and tearing the earth with their feet and horns, 



