1890.] 



ON THE DOMESTIC DOG. 



29 



We have already mentioned the fact that in the his-hly artificial 

 broad-headed dogs, elongation of skull and palate is a sign of impure 

 breeding, an evidence of admixture with the broad-headed strain 

 of that of some other and narrower-headed dog. Examples of this 

 may be seen almost any day in the streets in the shape of the half-bred 

 Pugs, in which the elongated muzzles present so great a contrast 

 with the short square faces of their pure-bred cousins. We have 

 no facts before us to prove whether the long-headed dogs such as 

 Greyhounds tend to become broader when impurely bred, but it is 

 highly probable that they would do so, and consequently that the 

 dogs at both ends of the scale would, under the influence of promis- 

 cuous interbreeding, tend to approximate to the average head. We 

 have thought that it might be useful to terminate this paper bv 

 giving a list of accessory molars noticed amongst the specimens 

 examined, being 1 76 in all. In concluding we may say that the 

 figures and calculations have been checked with care ; neverthele^s, 

 in dealing with so many figures it may be that errors may have 

 crept in. Should such be the case we much regret it with other 

 shortcomings of this paper. 



Table XXXVII. — Additional upper Molars. 



Variety of Dog. 



Sheep-dog 



Pointer 



Bull-dog 



Bull-dog 



Bull-dog 



Esquimaux 



Pug 



Span iel 



Black-aad-tan Terrier (cross-bred) 

 Black-and-tan Terrier (cross-bred) 



Lurcher 



West-Indian Dog 



In several of these specimens the additional molars had never 

 been cut but lay in crypts. 



