92 NATURAL SELECTION Iv 
ledge 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 distinctive characters in each group of insects. This 
complex apparatus, so different from anything in the eyes of 
vertebrates, may subserve some function quite inconceivable 
by us, as well as that which we know as vision. There is 
reason to believe that insects appreciate sounds of extreme 
delicacy, and it is supposed that certain minute organs, plenti- 
fully supplied with nerves, and situated in the subcostal vein 
of the wing in most insects, are the organs of hearing. But 
besides these, the Orthoptera (such as grasshoppers, etc.) 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 analogous sense. In flies, too, the third 
joint of the antenne contains thousands of nerve-fibres, which 
terminate in small open cells, and this Mr. Lowne believes to 
be the organ of smell, or of some other, perhaps new, sense. 
It is quite evident, therefore, that insects may possess senses 
which give them a knowledge of that which we can never 
perceive, and enable them to perform acts which to us are 
incomprehensible. In the midst of this complete ignorance 
of their faculties and inner nature, is it wise for us to judge 
so boldly of their powers by a comparison with our own? 
How can we pretend to fathom the profound mystery of their 
mental nature, and decide what, and how much, they can 
perceive or remember, reason or reflect! To leap at one 
bound from our own consciousness to that of an insect’s is as 
unreasonable and absurd as if, with a pretty good knowledge 
of the multiplication table, we were to go straight to the 
study of the calculus of functions, or as if our comparative 
anatomists should pass from the study of man’s bony structure 
to that of the fish, and, without any knowledge of the 
numerous intermediate forms, were to attempt to determine 
the homologies between these distant types of vertebrata. 
In such a case would not error be inevitable, and would not 
