TREATMENT OF BREEDING COWS. 231 



a former male — to ascertain, out of any given number of cases, 

 ill what proportion this effect is observed — and, generally, when 

 it is observed, to determine the circumstances under which it 

 holds, as also those under which it varies in different classes of 

 animals, or in different individuals of the same class." 



[Note. — We consider this theory of the "vitiation of the 

 blood" of the mother, by her blood connection with the foetus 

 in her womb, stated by Mr. M'Gillavray, as altogether too 

 "ingenious" and finely drawn. The "theory," however, has 

 had an existence, to more or less extent, among the popular 

 uneducated mind, perhaps from time immemorial. In our own 

 boyhood, more than fifty years ago, when there was a great rage 

 for introducing the blood of the Spanish Merino Sheep into the 

 flocks of the Eastern States, some farmers indulged the fancy 

 that if their coarse common ewes could be tupped by a Merino 

 ram, not only would the lamb be of half the Merino blood, but 

 the ewe herself partake of such proportion of his blood also, so 

 as to cause her future offspring, by whatever ram she might bo 

 connected, to retain a share of the Merino! How such an 

 absurdity should obtain credence we know not, otherwise than 

 by the same influence which created ghosts, spooks and witches. 



The foetus is enclosed in a case (placenta) within the womb, 

 and receives its nourishment only through the pecuUar organs 

 of the mother, which are in play during its location there. 

 That process is an extraordinary function of the female, active 

 only during pregnancy, and in no way common with her ordinary 

 habits. The theory would make the foetus, in the circulation of 

 its blood back into the system of the mother, a part of her own 

 organization, whereas, the foetus is only an offshoot of her sys- 

 tem, nourished by a peculiar internal process, or secretion, like 

 the milk she gives for its support after birth. 



If the blood of the foetus circulated, or were returned into the 

 veins of the mother, the foetus would be a part of herself, instead 



