56 HABITS AND INSTINCTS OP ANIMALS. CHAP. II. 



unnecessary. Their touch is still more defective, since 

 they have, in fact, no organs (like the fleshy tongue and 

 the naked muzzle of quadrupeds) adapted for convey- 

 ing this sense directly to their apprehension ; the feet, 

 more properly, being mainly intended for support, al- 

 though we may naturally suppose the soles possess a 

 slight degree of sensibility. Their power of hearing, 

 again, although superior to that they possess of touch, 

 is manifestly inferior to what is enjoyed by quadrupeds; 

 for, although the owls are remarkably gifted in this re- 

 spect, the ears of all other birds are small, and are with- 

 out that external appendage for facilitating the trans- 

 mission of sound into the tympanum, which is so very 

 general among the Mammalia. 



(72.) If we turn to quadrupeds, however, we per- 

 ceive, not the pre-eminent development of any one 

 sense, but an equal one of all. Their sight, although 

 inferior to that of birds, appears, nevertheless, superior 

 to that of all the other Vertebrata, fishes, probably, ex- 

 cepted as the wandering life of that class assimilates 

 them very much to birds ; while in their sense of touch, 

 of taste, and of hearing, there is every reason to be- 

 lieve they surpass all others of the vertebrated animals. 

 These comparisons, therefore, establish our proposition, 

 namely, that, in every pre-eminently typical group, we 

 find a union of all the higher qualities shared by others 

 of its own circle, although each quality is not in the 

 same proportion as may be found within the same 

 range. Of the senses of fish and of reptiles, we know 

 too little, indeed, to judge of what may be their pecu- 

 liar gifts ; but, if we may be guided by many analogies 

 presented by the leading facts of animal economy, we 

 should be disposed to conclude that they each possessed 

 some one sense preponderating over the others, just as 

 we have shown in the class of birds. We shall now 

 proceed to point out a few of the most prominent and re- 

 markable instances in the senses of annulose animals. 

 (73.) All Insects*, properly so called, possess the 



* Our definition of a true insect, as opposed to that of some modem 



