86 



PROCEEDINGS OF THE ACADEMY OF 



I. 



[1893. 



with other facts, that there has been a process of degeneration at 



work in reducing the proportional volume of the musculature of 



the body and urosome in the double-tailed races. Table II gives 



the height of this frustum of a cone to which I have compared the 



musculature of the body, as well as the major diameters of the base 



and apex of the frustum in millimetres, for each race in absolute 



measurement. 



II. 



In a third table I have attempted to represent the proportions of 

 the several parts to each other, but from tables I and II, I obtain 

 data for a more general and final fourth table in which the individ- 

 uals are supposed to be of the same age, and more nearly of the 

 same size and weight than was the material at my disposal. 



