26 PROF. B. C. A. WINDLE AND MR. J. HUMPHREYS [Jan. 14, 



these is doubtless true also in lesser degree of the greater number 

 of specimens coming under examination. It thus becomes appa- 

 rently a hopeless task to look for evidence as to the proximate or 

 ultimate derivation of the breeds of domestic dogs in their skulls 

 or teeth. 



Some points of interest may, however, be learnt from a comparison 

 of certain of the measurements, and with these we now proceed to 

 deal in order. 



Relative Breadth and Length of Skulls and Palates. 



In the tables next to follow we have endeavoured to classify the 

 skulls according to their relative breadth and length and according 

 to that of their palates. An index has in each case been taken by 

 using the formula 



Width X 100 

 Length 



In the first instance this has been applied to the measurements 

 " total length " and "zygomatic width." Those dogs of which the 

 index is above the average are those possessed of short, broad heads, 

 whilst those below are in varying degrees long and narrow-headed. 

 A distinct group placed near to but slightly below the average, may 

 be' looked upon as occupying a medium position between the two 

 extremes. The second column, which has been placed side by side 

 with the first for the sake of more easy comparison, deals with the 

 relative size of the palatine surface. The first column, whilst con- 

 veying a good idea of the relative length and breadth as they 

 appear in the living animal, conveys at the same time a somewhat 

 incorrect idea of the actual condition, since it is dependent upon the 

 amount of projection of the zygoma, which is obviously a more or 

 less variable factor. A comparison of the two columns shows how 

 much some skulls owe their apparent breadth to zygomatic projec- 

 tion. It also shows that the broadest and narrowest heads fall into 

 nearly the same positions in both columns, those intermediate 

 between the two extremes showing greater discrepancies. Some of 

 the figures are from the measurements of single specimens ; in cases 

 where more than one has been examined the measurements are 

 averages. 



It will be noticed that the distinctly broad-headed dogs form a 

 well-marked group by themselves, including the Chinese Pug-nosed 

 Spaniel, the Pug, Bull-dog, Black-and-tan Toy Terrier, and King 

 Charles' Spaniel, a considerable interval existing between these and 

 the next. All these, it will be noticed, are highly artificial breeds 

 which require great care and attention to be bestowed upon them to 

 prevent deterioration with its consequent elongation. Next to this 

 group comes one largely consisting of Terriers with heads inclining 

 to be broad. A miscellaneous group next follows gradually de- 

 creasing to the distinctly narrow-headed dogs such as the Irish 

 Wolf-dog and the Greyhound. It is interesting to notice the 



