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 commonly found in 

 different breeds are subject to much variation. 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 



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



