GENETIC TYPE AND THE ENDOCEINES 217 



the teeth are more closely set and crowded together in the 

 jaws of the Boston terrier than in either the French or 

 English bulldogs. The relations in size of premolar teeth 

 to extent of premolar regions differ more among these three 

 breeds than does any other characteristic charted. 



It will be noticed in this chart that while all other indices 

 are high, indicating short wide skulls, the upper facial index 

 is low. This is due to the fact that the upper facial index 

 was calculated in a manner the opposite to that used for 

 the other indices, that is, the upper facial index was based 

 on nasal length divided by palatal width while in general 

 the indices were determined by dividing widths by lengths. 

 The manner of calculating these indices was reversed simply 

 as an aid for contrasting the types, as we shall see beyond. 

 This index is also reversed in the two previous charts. 



An inspection of text-figure 53 as a whole shows that the 

 bulldog skulls are uniformly close together and exhibit an 

 harmonious type agreement quite equal to that for the 

 shepherd, foxhound and Saluki skulls (text-fig. 51). Although 

 the bulldog skulls are highly aberrant in form and very 

 abnormal, with pronounced structural disharmonies, they 

 nevertheless constitute a definite type with clear cut char- 

 acteristics. 



Finally, the position of the anterior inferior dental alveolus 

 is indicated below the sagittal outlines at the top of text- 

 figure 53. The lower jaw of the English bulldog projects far 

 in front of the upper jaw; the prognathism of the mandible 

 in the French bulldog is not quite so pronounced; and, as 

 a breed characteristic in the Boston terrier, the incisor teeth 

 are in opposition, since the upper and lower jaws are almost 

 equal in length. 



A final chart of this series was made to contrast in a 

 graphic way the indices and dimensions of representative 

 skulls from the two different types found in text-figures 51 

 and 53. In text-figure 54, the skull indices and dimensions 

 of the standard German shepherd skull are arranged beside 

 the values for the same characteristics in the English bulldog 

 skull. At the top of this figure, the sagittal outlines of these 



