114 PHILOSOPHY OF ZOOLOGY. 



perusal of the description of a mineral, plant, or animal, to 

 judge accurately of its colour, from the terms in which it 

 was expressed. This evil is in a great measure removed, by 

 the introduction of tables of colours, with examples. The 

 best of these, for the purposes of natural history, and one 

 which, we believe, to be extensively used, is executed by Mr 

 SYME of Edinburgh, an accomplished painter of objects in 

 natural history, and an accurate judge of colours *. It is 

 a work which every naturalist should possess ; and it would 

 be of very great advantage to science, were it generally 

 adopted as a standard of colours. 



2. Dimensions. In all animals there is a determinate 

 size, which the body, if in health, and placed in favourable 

 circumstances, is destined to attain. A knowledge of the 

 dimensions of an individual is, therefore, of great use in en- 

 abling us to ascertain the species to which it belongs. This 

 is a character, however, which ought to be employed with 

 caution, as the circumstances on which its value depends 

 are subject to much variation. Young animals are smaller 

 than old ones, and often exhibit a different proportion of 

 parts. The males, in quadrupeds, are larger than the 

 females ; while, among insects, and even some birds, the 

 females exceed the males in their dimensions. But even 

 in the individuals of the same species, climate exercises a 

 powerful influence. When near the limits of their geo- 

 graphical distribution, the growth is counteracted, the rela- 

 tive dimensions of the parts vary, and the ordinary stand- 

 ard of size ceases to be a criterion of the species. 



* " Werner's Nomenclature of Colours," by PATRICK SYMF, flower- 

 painter, Edinburgh ; painter to the Wernerian and Horticultural Societies of 

 Edinburgh, 1 vol. 12mo, 1814. 



