210 CHARLES R. STOCKAED AND A. L. JOHNSON 



Aii appreciation of the extent of the character differences 

 among the many dog types may be clearly brought out by 

 comparing the first four indices at the top of table 1 for the 

 Saluki and German shepherd dog, with the same indices for 

 the English bulldog, the Pekingese and the Brussels griffon. 

 The cranial index for the Saluki is 64, and for the German 

 shepherd only 51 ; while in the English bulldog this index 

 is 69, and in the Pekingese and Brussels griffon 84. The two 

 dogs last mentioned have wide, almost spherically shaped 

 cranial cases which are in strong contrast to the long, narrow 

 cranium of the shepherd dog. In spite of the general linear 

 type of the Saluki it would seem to have a somewhat more 

 rounded cranium than the shepherd dog, but this is an ap- 

 parent rather than a real condition and is due entirely to 

 the fact that the shepherd skull has a high dorsal crest and 

 prominent supraoccipital spine, which adds to its length; the 

 Saluki skull is flat dorsally and lias almost no crest or spine. 



The second index in the table represents the skull as a 

 whole and is calculated on the basis of the relation of zygo- 

 matic width to length of skull base (pi. 35, fig. 1, F; fig. 2, 

 D-G). The skull index for the Saluki and German shepherd 

 dog is only 56, while for the bulldog and Pekingese it is 107, 

 and for the Brussels griffon 103. The three latter skulls 

 have indices almost double that of the shepherd. The bulldog- 

 like skulls are wider than long and the shepherd skull is 

 often twice as long as wide. These must be recognized as 

 enormous differences in the head shapes occurring within a 

 single species. 



The palatal index, determined on the basis of palatal width 

 to length, is 60 for the German shepherd as against 122 for 

 the bulldog and Pekingese and 125 for the Brussels griffon. 

 The palatal indices of the short skulls are more than double 

 that of the shepherd. 



The fourth line of figures in table 1 represents the snout 

 indices. These indices are based on the relation of the width 

 at the alveolar border of the maxillary canine teeth (pi. 35, 

 fig. 1, C) and the length of the snout (pi. 35, fig. 3, J-F). 



