GENETIC TYPE AND THE ENDOCRINES 135 



study of their skull and other features than for the simple 

 inheritance of the achondroplasic extremities. However, they 

 add material to further substantiate the results recorded in 

 previous pages. Examination of plate 46 (p. 261) will show 

 the manner of short leg' inheritance following the cross of 

 these two pure stocks. The dachshund (fig. 1) and French 

 bulldog (fig. 2) are beautifully contrasted types and the F x 

 hybrids (figs. 3 and 4) are almost indistinguishable from the 

 F x dachshund-Boston terriers. Four litter mate F 2 animals 

 are seen in figures 5 to 8, and the same four specimens, care- 

 fully mounted, are shown in plate 47 (p. 263), each facing 

 its own skeleton which was arranged to stand in as closely 

 comparable a position as possible. The short, wide scapula 

 and short legs deviate from the normal long legged skeletons 

 in the same ways as those with which we are familiar from 

 previous descriptions of extremity skeletons. 



Dachshund-Brussels Griffon Cross for Extremity Types 



This cross was also made primarily for its importance in 

 an analysis of skull types and their modifications. Inciden- 

 tally, however, it supplied further data on inheritance of 

 contrasted conditions in the extremities. 



The Brussels griffon is a tiny midget dog with a flat 

 monkey-like face. Many specimens have practically no muzzle 

 and lack entirely the normal protruding jaws of the dog. 

 The legs of this midget are long, slender and straight. When 

 crossed on the dachshund the short achondroplasic extremities 

 are inherited by the hybrids as a single factor dominant 

 character just as has been found in all other crosses. Figures 

 1 and 2 in plate 33 illustrate the extremely contrasted fea- 

 tures of the two pure breeds. Figure 3 shows the F x hybrid, 

 and figures 4 to 7 animals derived from a backcross of the 

 Fj on the dachshund parent. The extremities seen in these 

 illustrations are exactly what would be expected from previous 

 experience. 



