GENETIC TYPE AND THE EXDOCRIXES 



379 



almost total facial index. Text-figure 74 shows the range for 

 this index among the several occlusal groups. This figure is 

 strongly contrasted with text-figure 73 for cranial indices. 

 The highest muzzle index with normal occlusion is 96, but 

 this is exceptional; the forty-eight other skulls of this normal 

 group range from 81 down to 51. In other words, only one 

 member of the normal group has a muzzle almost as wide 

 as it is long; in the others the muzzles are anywhere from 

 slightly longer than wide to twice as long as wide. In contrast 



Zoo - 

 /?o - 



ISO- 

 170- 

 /60- 

 ISO- 



/fO- 



m- 



J20- 

 110- 



ioo- 



Text- 

 divided 



figure 74. Relation of dental occlusion to tnuzzli 

 into groups as indicated in text-figure 72. 



F G 



to this, the malocclusal groups show very high muzzle indices 

 reaching almost 200 in value, that is, the muzzles are nearly 

 twice as wide as they are long. Group E, composed of skulls 

 witli decided mandibular prognathism, ranges for muzzle 

 index from 193 down to as low as 73, but only six of the 

 twenty-nine specimens have indices under 100. Therefore, 

 all twenty-nine skulls have shorter muzzles than those of the 

 normal group. The groups in text-figure 74 indicate that 



