266 PRINCIPLES OF STOCK-BREEDING. 



derived from its male parent, and that the female may 

 communicate these, with those proper to herself, to the 

 subsequent offspring of a different male parentage." l 



Mr. James McGillivray, a veterinary surgeon of 

 Huntly, presents essentially the same theory, as he 

 believes that, when a female of any pure breed has 

 been impregnated by a male of another breed, she be- 

 comes a cross, " the purity of her blood being lost in 

 consequence of her connection with the foreign ani- 

 mal." 9 



Dr. Harvey, who had advocated the same theory, 

 afterward observes : " Since then I have learned that 

 many among the agricultural body in this district are 

 familiar, to a degree that is annoying to them, with 

 the facts there adduced in illustration of it finding 

 that after breeding crosses their cows, though served 

 with bulls of their own breed, yield crosses still, or 

 rather mongrels ; that they were already impressed 

 with the idea of contamination of blood as the cause 

 of the phenomenon ; that the doctrine so intuitively 

 commended itself to their minds, as soon as stated, 

 that they fancied they were told nothing but w T hat 

 they knew before." 3 



If the influence of the male upon the offspring of 

 the same mother by another male were limited to the 

 class of mammals, this theory might be accepted as 

 a plausible explanation of the cases that have been 

 presented ; but there are instances in which a similar 



1 " Human Physiology," p. 970. . 



2 " Principles of Breeding," p. 52. 



3 Edinburgh Journal of Medical Science, 1849, as quoted by Goodalc, 

 loc. cit. t p. 63. 



