GENETIC TYPE AND THE ENDOCRINES 211 



This snout index is 60 for the long German shepherd skull 

 and only 53 for the narrow muzzled Saluki skull, as contrasted 

 with 171 for the bulldog-, 179 for the Pekingese, and 183 for 

 the Brussels griffon. No other index calculated, with the 

 possible exception of the upper facial index, shows such 

 enormous deviations from the control or standard shepherd 

 type. 



The differences shown in three of the above four indices 

 between the wild or ancestral typed dog skull and the di- 

 vergent or mutant types are of such magnitude that con- 

 fusion of the types would be impossible. 



It is unnecessary in this text to further pursue the details 

 of table 1 ; the significance of the figures is sufficiently clear 

 and they can be followed by the reader to his own satisfaction. 

 However, it is very difficult to make comparative estimates 

 of values among the large numbers of detailed measurements 

 contained in the table, and we have attempted to express 

 these in graphic fashion by the charts discussed below. 



Graphic Comparisons of Measurements and Indices Among 

 Similar and Contrasted Skull Types 



In this section, groups of similar typed skulls will be com- 

 pared, in order to discover how closely alike they are in 

 their indices and dimensions, and also which characteristics 

 are most variable or likely to differ among even those breeds 

 of the same general type. For this purpose we separated and 

 classified the skulls according to outstanding characteristics 

 of size, structure, etc. The first group contains the long typed 

 skulls, those from the German shepherd, the foxhound and 

 the Saluki. These three breeds have standard wolf -like skulls 

 which may be thought to represent the original wild type 

 from which the modified skulls have been derived. 



The St. Bernard, great Dane and dachshund make up the 

 second somewhat divergent group of skulls. Although the 

 St. Bernard is of giant size with definite acromegalic symp- 

 toms, the basic type of the skull is closely similar to that of 

 the simple giant great Dane and, strange to find, both these 





