218 CHARLES R. STOCKARD AND A. L. JOHNSON 



two skulls are given. The outline of the shepherd skull forms 

 a long pattern which is strongly contrasted with that of the 

 shortened and proportionately much higher outline of the 

 English bulldog skull. The contrast is further emphasized 

 when these two outlines are compared with those shown at 

 the top of the three previous charts. 



The indices and measurements represented by the columns 

 in text-figure 54 were furnished by the skulls of seven pedi- 

 greed pure-line German shepherd dogs and nine pedigreed 

 English bulldogs. The chart as a whole shows great differ- 

 ences in height between the diagonal columns representing 

 the shepherd characteristics and the cross-hatched columns 

 representing those of the bulldog. The skull index, palatal 

 index, snout index, upper facial index and mandibular index 

 all show wide differences for these two skull types. The 

 cranial indices of the two breeds differ in the same direction 

 though not so strongly. The upper facial index, as mentioned 

 before, was calculated in a manner the reverse of that for 

 the other indices, and thus appears high for the shepherd 

 and low for the bulldog. This index is widely different in the 

 two skull types. 



The breadth-height index (distance from auditory meatus 

 to bregma divided by cranial width) gives no contrast between 

 the breeds and is an insignificant feature. The relations of 

 zygomatic width to the width of frontal bone and of frontal 

 width to parietal width are about the same for the two 

 types and are also insignificant. The right half of the chart 

 illustrates the almost complete inadequacy of linear measure- 

 ments for differentiating types among strongly contrasted 

 skulls. The zygomatic widths are the only linear measure- 

 ments which give a true picture of the variations between 

 these two highly different types of skulls. 



The degree of variability above and below the average for 

 the measurements shown in the chart is again represented 

 by the blank space at the top of each column. The bulldog 

 skull is much more variable in all the characteristics rep- 

 resented in the chart than is the skull of the shepherd, with 

 possibly one or two insignificant exceptions. This instability 



