GENETIC TYPE AND THE ENDOCRIXES 91 



the quality of the leg bones in this breed as contrasted both 

 structurally and genetically with the comparable characters 

 in the bassethound. 



The legs of the English bulldog are short and sturdy and 

 the front legs are set far apart, making the chest appear 

 extremely wide and giving rise to the term "bench-legged." 

 Figure 1 in plate 18 is a good illustration of this condition 

 in the legs of a highly prized champion specimen of the breed, 

 "Lome's Latest" A.K.C. 651313, our 903 6, which has been 

 used in these experiments as a sire. The legs are perfectly 

 straight boned and show no evidence of twist in growth and 

 no overhang at the wrist or abduction of the foot. In other 

 words, there is no evidence of achondroplasic growth in the 

 long bones of the extremities in the bulldog. This fact is of 

 great interest since the skull, tail and at times other regions 

 of the axial skeleton show the most exaggerated conditions 

 resulting from pronounced chondrodystrophy. These facts, 

 as we shall emphasize in later sections, form an ideal contrast 

 with the bassethound which, as we have seen, shows chondro- 

 dystrophy in the appendicular skeleton and perfectly normal 

 development in the axial skeleton. 



Test for absence of achondroplasia in the legs of the bulldog. 

 In order to be genetically certain that the bulldog had no 

 factors for chondrodystrophy in the long bones of the ex- 

 tremities, a test cross breeding with the control type German 

 shepherd dog was made. From evidence in the experiments 

 already discussed it could be presumed that if the bulldog 

 had any basis for achondroplasia of the legs this would show 

 itself in the hybrids from the shepherd cross. Another possi- 

 bility suggested itself: even though the bulldog might have 

 no basis for achondroplasia of the legs, the highly expressed 

 achondroplasia localized in the axial skeleton might possibly 

 become generalized and spread to other skeletal parts on 

 hybridizing. A test of this possibility was highly desirable. 



A pure German shepherd bitch, 118 9 , of perfect long leg 

 type, a niece of the bitch shown in plate 18 (fig. 2), was mated 

 with the champion bulldog pictured in figure 1. Three pups, 



