20 ESSAY ON CLASSIFICATION. 



those peculiarities which at the same time distinguish it ? 

 Does not the existence of a rudimentary eye discovered 

 by Dr. J. Wyman in the blind fish show, on the contrary, 

 that these animals, like all others, were created, with all 

 their peculiarities, by the fiat of the Almighty, and that 

 this rudiment of eyes was left them as a remembrance of 

 the general plan of structure of the great type to which 

 they belong ? Or will, perhaps, some one of those natu- 

 ralists who know so much better than the physicists what 

 physical forces may produce, and that they may produce, 

 and have produced every living being known, explain 

 also to us why subterraneous caves in America produce 

 blind fishes, blind Crustacea, and blind insects, while 

 in Europe they produce nearly blind reptiles ? If there 

 is no thought in the case, why is it, then, that this very 

 reptile, the Proteus anguinus, forms, with a number of 

 other reptiles living in North America and in Japan, one 

 of the most natural series known in the animal kingdom, 

 every member of which exhibits a distinct grade 1 in the 

 scale I 



After we have freed ourselves from the mistaken im- 

 pression that there may be some genetic connection be- 

 tween physical forces and organized beings, there remains 

 a vast field of investigation, to ascertain the true relations 

 between both, to their full extent, and within their natural 

 limits. 2 A mere reference to the mode of breathing of 

 different types of animals, and to their organs of locomo- 

 tion, which are more particularly concerned in these rela- 

 tions, will remind every naturalist of how great import- 

 ance in Classification is the structure of these parts ; and 

 how much better they might be understood, in this point 

 of view, were the different structures of these organs more 



1 See below, Sect. 12. 2 See below, Sect. 16. 



