Insects. 1565 



the inductive sciences together. Without it they would all sink, 

 and Geology, which is entirely built upon it, would be the very first 

 to fall. Once, in fact, remove analogy, and there is an end to 

 all sound and legitimate deductions, for it strikes at the very root of 

 reasoning and upsets the principles on which we proceed. If our legs 

 are known to be organs of locomotion, and certain members of other 

 animals are observed to be organs of locomotion also, acting on the 

 same principle and for the same purpose, these organs are called 

 " legs " and are said to be " analagous " to our own, having (in the 

 words of jthe very definition of analogy) " a similar relation of func- 

 tion." If the eyes of insects are observed by the anatomist to be form- 

 ed on the same principle as our own, — • if they possess the fluids ne- 

 cessary for the formation of proper refracting media, and a retina, 

 stretched out behind, to receive the impression formed by the rays of 

 light, refracted through the fluids, upon its surface, — then are the eyes 

 of insects said to be " analogous " to our own eyes, having, as in the 

 case of the legs, " a similar relation of function." And so it is with 

 the nervous system. The greatest physiologists of the day have al- 

 lowed it to be the surest basis of arrangement throughout the whole 

 animal kingdom ; and, arguing from the analogy which the general 

 systems bear to our own, have separated it into the five grand depart- 

 ments which are recognized by all. Surely then Mr. Turner cannot 

 accuse me of " building on probabilities and theories," in arguing, in 

 my former paper, on an analogy which cannot be rejected without up- 

 setting the very groundwork on which modern physiologists have so 

 cautiously and judiciously advanced. I admit all his facts on the 

 " struggles of impaled Lepidoptera," and read them with interest and 

 delight. I look upon them as strong proofs of what I have already 

 stated, but I can not consider them in any other light. And I 

 can only express a hope that those entomologists who are preju- 

 diced in favour of what I believe to be a solely entomological theory, 

 — the insensibility of the insect world, — will at least consent to view 

 the subject in a broad light, and examine both sides of the question 

 before they finally decide on so large and important a subject. 



T. V. Wollaston. 

 Jesus College, Cambridge. 



