THEORY OF GENERATION. 209 



there reason to believe that it is so prejudicial in the domestic 

 animals as in man, with whom the adoption of the practice seems 

 especially to be avoided, and has been forbidden by most of our 

 lawgivers, human and divine. 



15thly. Many physiologists believe that the influence of the 

 first impregnation extends to the next and subsequent ones. 

 Haller was the first to remark, that a mare which has bred a mule, 

 begotten by an ass, if put to a horse the next time, will often 

 again breed a mule. Recent experiments have also shown that a 

 mare which had been put to a male quagga for three years, sub- 

 sequently bred several foals by an Arabian horse, which showed 

 the quagga markings, though each time more and more faintly. 

 Burdach has remarked the same in the sow and bitch, and in the 

 human female the observation has frequently been made, but of 

 course in none is it so strongly marked as in the mule and quagga. 

 If these facts are correctly stated, it is highly important to guard 

 against a brood bitch being warded at any time by a mongrel, or 

 even by a badly-bred greyhound. 



It will thus be seen that, though few, there are some brood 

 landmarks which may serve to guide the breeder, and that by 

 studying them he may hope to avoid the grievous errors so often 

 made by those who think breeding in all cases a complete lottery. 

 Indeed, by those who pride themselves most upon their experience 

 and success, it is very commonly supposed that the breeder has 

 nothing to do but to correct any defect in his bitch by fixing 

 upon a stallion which possesses in an eminent degree the quality 



