164 



THE DOMESTIC DOG. 



shortening of the facial portion of the skull, entailing, as it does, a 

 variety of other modifications to afford adequate space and attachment 

 for the vigorous muscles which give the animal its prodigious power 

 of grip. 



Fig. 42. 



Skull of a Bull-dog. 



The cranial and dental conditions which are commonh^ found^in 

 different breeds are subject to mucli va riation. Dr. Windle and Mr. 

 John Humphreys, who have gone, with exceeding care, into this question, 

 tell us*: — "The range of variation (as to skull and teeth) in any 

 breed is much greater, in almost every case, than that existing between 



* Troe. Zool. Soc. 1890, pp. 24 & 26. 



