THE SIRE. 101 



of the same blood is the usual extent to which it is car- 

 ried, as the life of the animal is the limit ; and it is a 

 remarkable fact, that, in practice, a conclusion has been 

 arrived at which exactly coincides with these natural 

 laws. ' Once in and once out ' is the rule for breeding 

 given by Mr. Smith in his work on the breeding for the 

 turf; but twice in will be found to be more in accord- 

 ance with the practice of our most successful (early) 

 breeders. 



*' 15. The influence of the" first impregnation seems 

 to extend to the subsequent ones : this has been proved 

 by several experiments, and is especially marked in the 

 equine genus. In the series of examples preserved in 

 the Museum of the College of Surgeons, the markings 

 of the male quagga, when united with the ordinary 

 mare, are continued clearly for three generations beyond 

 the one in which the quagga was the actual sire ; and 

 they are so clear as to leave the question settled without 

 a doubt. 



"16. When some of the elements of which an indi- 

 vidual sire is composed are in accordance with others 

 making up those of the dam, they coalesce in such a 

 kindred way as to make what is called 'a hit' On the 

 other hand, when they are too incongruous, an animal 

 is the result wholly unfitted for the task he is intended 

 to perform." 



The above rules, or " principles " as the author names 

 them, appear to me to be in the main correct, and of 

 great value to the student of the question ; but they do 



