GENETIC TYPE AND THE ENDOCRINES 637 



The production of mixed constitutional types by cross 

 breeding- opposite normal types gives us some basis for an 

 understanding of the English bulldog. This dog has peculiar- 

 ities not found among the normal types. It has behavioral 

 characteristics of both polar groups as well as some not 

 found in either group. Its physical form is also a mixture 

 of opposite types. As Section III (Stockard on undershot 

 jaws) emphasizes, physical disharmonies similar to that found 

 in the head of the bulldog have been produced experimentally 

 by crossing two widely different types. One such case was 

 the cross of the short nosed Pekingese witli the long nosed 

 dachshund. Among the F x s there was but little variation in 

 the jaws, but in the F 2 s many examples of abnormal jaw 

 conditions are shown. It would seem that some of these F 2 s 

 inherit the short nose of the Pekingese and the long mandible 

 of the dachshund, giving the same condition found in the 

 bulldog. This suggests the possibility that the abnormal jaws 

 of tlie bulldog came about by crossing a long nosed dog with 

 a short nosed dog. Basically the bulldog seems to be a hound 

 type. The bodily shape of the English bulldog is more like 

 the round bodied or hound dog than any other breed, and 

 the mandible of the bulldog is like that of the bassethound 

 ( Section III). Xot enough of the history of the English bulldog 

 is known to be certain that it did originate from a hound, 

 but the above experiments with the dachshund and Pekingese 

 indicate clearly how similar types can be produced. 



In addition to the abnormal head, the bulldog has an ab- 

 normal condition of the vertebrae of the tail. This "screw" 

 tail is a regional abnormality inherited as a recessive char- 

 acter (p. 387, Stockard). The bulldog, then, seems to have a 

 round shaped body, with long legs and definite abnormalities 

 at both ends of the axial skeleton. This suggests that the 

 bulldog results from mixing different breeds, leading to an 

 inharmonious blending of the physical characters. An analysis 

 of the glands of this dog, reported in Section V, shows 

 specifically that these also deviate widely from the normal 



