42 SOME THOUGHTS ON CLASSIFICATION 



a sort of representation of the various functions or systems of parts of 

 man, the highest animal, amongst the lower orders, some one function 

 predominating, according to his view, in each division. "Whilst per- 

 suaded that the idea of subdividing the vital functions of the most 

 perfect animal, and arranging groups of animals in which each pre- 

 dominates and gives character to the structure is too fanciful for use- 

 fulness, and that Oken has wrongly treated as leading functions, the 

 several branches of the nutritive, whilst it is hardly true that those 

 branches are specially represented in the divisions to which he has 

 assigned them ; I cannot but feel that the conception of the predomi- 

 nance of a particular vital function in a great division of the animal 

 kingdom, giving it its special character, is a just and noble one, and 

 cannot fail to contribute greatly to the progress of a truly natural 

 system. 



I do not know of any principle so certainly misleading in the classi- 

 fication of organised beings as that of requiring that every object in a 

 certain division should strictly conform to all its distinctions as they 

 must be laid down in giving a general view of it. The common char- 

 acter represents a cluster of tendencies all clearly manifested in the 

 most typical examples, but losing their power in remoter forms which, 

 nevertheless, have something about them which does not permit their 

 removal from the group. Thus is produced that shading of all natural 

 divisions into each other and that abundance of transition forms which 

 so conspicuously mark the order of nature. I maj'- illustrate this 

 remark by observing that I have noticed its being accounted a suffi- 

 cient objection to Professor Owen's primary divisions of Mammals 

 according to the development of the brain, that some which are placed 

 in Gyrencephala do not display the gyrations which form the leading 

 character, as for instance the small lemurs and some of the minute 

 monkeys. Surely, however, if these animals are admitted to be most 

 closely allied to such as do display the gyrations, and are at the same 

 time both among the lower forms and of small size, the fading out of 

 the character is sufficiently accounted for, and we are obliged to be 

 content with a general characteristic, though it does not yield a rigid 

 definition. With respect to the remainder of these great divisions, 

 Lyencephala is supported by abundant confirmatory characters, and 

 has hardly been called in question. As to Archencephala it would be 

 interesting to see Professor Owen's reply to the charge of falsehood in 

 statements which have at least the appearance of probability ; but I 



