254 



CHARLES R. STOCKARD AND A. L. JOHXSOX 



in text-figure 57. The snout index, as we may recall, is the 

 character which presents the widest differences between the 

 normal long skulls and the short bulldog typed skulls. The 

 difference in palatal indices for the two types is also very 

 great. 



fa— 

 So — 



PALATAL INDEX 



Text-figure 58. Dachshund-Boston terrier cross. Each vertical line represents 

 an index based on exact measurements of the skull. The series of skulls for 

 these frivo charts is the same as used for text-figure 57. A, dachshund; B, Boston 

 terrier; C, F t ; D, F,,; E, backcross of F, with the Boston terrier; F, backcross 

 of F, with the dachshund. 



The long, narrow snout of the dachshund gives a very low 

 index, which ranges from 59 to 66 for the four skulls rep- 

 resented. In wide contrast to this, the four Boston terrier 

 skulls range from 136 to 160, the indices being between two 

 and three times higher than for the dachshund skulls. The 

 snout indices in the three Fj skulls are very variable as com- 

 pared with the three other indices discussed above. The 

 features controlling this index are very delicate in their re- 

 sponse, and their expression is dependent upon the degree of 



