GENETIC TYPE AND THE ENDOCRIXES 



203 



in length between the portion of the cranium anterior to the 

 bregma and that posterior to it. There is also no correlation 

 between either of these cranial measurements and the length 

 of the bony nose or the length of the snout. 



to 



* 



<3Q 



5b 



2o 

 /O 



Text-figure 48. Sequence M. Bregma to supraoccipital spine. Same skull 

 sequence as text-figure 45. 



LENGTH OF SKULL BASE IN RELATION TO ANTEROPOSTERIOR 

 LENGTH OF PREMOLAR TOOTH CROWNS 



The lengths of skull base in this group of skulls range 

 from 210 mm down to 67 mm, the extremes differing as 

 3.13:1. It seemed a matter of possible importance to deter- 

 mine whether the size of teeth, as indicated by anteroposterior 

 dimensions of the tooth crowns, could be directly correlated 

 with the total skull length. The number of teeth or dental 

 formula is quite uniform in all dog breeds and, since this is 

 the case, an animal with a long jaw would need larger teeth 



