GENETIC TYPE AND THE ENDOCRINES 259 



Both sets of curves indicate that in general the individual 

 features of the long normal dachshund typed skull tend to 

 dominate comparable features in the short wide skull of the 

 Boston terrier. 



The Behavior of Skull Characteristics in the French 

 Bulldog-Dachshund Hybrids 



A second cross was made between the dachshund and 

 another dog of bull type, the French bulldog, in order to 

 discover whether the hybrid reactions would be similar to 

 those in the cross between the Boston terrier and dachshund. 

 The French bulldog is somewhat different from the Boston 

 terrier and is a more pronounced bull type. F l hybrids were 

 again produced by crosses in both directions, and their general 

 type and appearance were the same whether the dam used 

 was a dachshund or a French bulldog. 



Plate 46 illustrates the general appearance of the two pure 

 parent stocks as well as that of their F a and F 2 hybrids. 

 Through the descriptions in connection with the foregoing- 

 cross we are familiar with the dachshund characteristics 

 (tig. 1). The French bulldog (tig. 2) is a European breed 

 frequently spotted dark brindle and white, but in this country 

 it is usually bred for a uniform brindle pattern. The head 

 is much heavier and of more pronounced bull type than is 

 the head of the Boston terrier. The mandible is prognathous 

 or undershot, projecting beyond the maxilla in the same way 

 as is strongly presented by the English bulldog. The forehead 

 is high and rounded, and the eyes are somewhat exophthalmic, 

 though not to so great a degree as in the Boston terrier. 

 The rounded bat-like ears are carried erect. In action and 

 behavior the French bulldog is not generally so nervous 

 nor so excitable as the Boston terrier. 



The two Fj French bulldog-dachshund hybrids (figs. 3 and 

 4, pi. 46) are, in the photographs, almost indistinguishable 

 from the F a Boston terrier-dachshund hybrids seen in plate 

 29 (p. 127). So close is the resemblance that it is very difficult 



