202 ON INSTINCT IN MAN AND ANIMALS. 



animals not very far removed from ourselves, before 

 we pronounce positively as to the nature of the mental 

 operations in creatures so radically different from us 

 as insects. We have not yet even been able to ascer- 

 tain what are the senses they possess, or what relation 

 their powers of seeing, hearing, and feeling have to 

 ours. Their sight may far exceed ours both in delicacy 

 and in range, and may possibly give them knowledge 

 of the internal constitution of bodies analogous to that 

 which we obtain by the spectroscope ; and that their 

 visual organs do possess some powers which ours do 

 not, is indicated by the extraordinary crystalline rods 

 radiating from the optic ganglion to the facets of the 

 compound eye, which rods vary in form and thickness 

 in different parts of their length, and possess distinc- 

 tive characters in each group of insects. This complex 

 apparatus, so different from anything in the eyes of 

 vertebrates, may subserve some function quite incon- 

 ceivable by us, as well as that which we know as 

 vision. There is reason to believe that insects appre- 

 ciate sounds of extreme delicacy, and it is supposed 

 that certain minute organs, plentifully supplied with 

 nerves, and situated in the subcostal vein of the wing 

 in most insects, are the organs of hearing. But be- 

 sides these, the Orthoptera (such as grasshoppers, 

 &c.) have what are supposed to be ears on their fore 

 legs, and Mr. Lowne believes that the little stalked 

 balls, which are the sole remnants of the hind wings 

 in flies, are also organs of hearing or of some ana- 

 logous sense. In flies, too, the third joint of the 



