ANATOMY AND PHYSIOLOGY. 87 
It is the same difficulty as appears with regard to 
the eyes of insects; we cannot understand how so 
small a nose can smell, any more than how such 
imperfect eyes can see so acutely. There are more 
things in Insect Physiology than can be explained 
by the physiology of the higher animals. Yet we 
must not ignore those physiological principles. La- 
treille* assigned the faculty of smell to the antenne. 
But all analogy is against this conclusion. We may 
admit that the rule which requires a well-developed 
nose for a strong scent, and a well-developed brain 
for a strong intellect, and which expresses the points 
of a horse in the terms of anatomy, is not altogether 
applicable to insects; though we cannot tell exactly 
why. But the physical objections to his theory are 
very strong. Moisture seems an indispensable requi- 
site for a part which is to appreciate odorous particles, 
and that is singularly wanting on the receiving sur- 
face of the antenne. 
Spence’s supposition that there is a peculiar organ of smell inside 
the mouth, assigns the faculty, not to the mucous membrane lining the 
rest of the mouth, but to that lining the trachez. 
* Newport, ‘On the Antenne,’ sup. cit. p. 231. 
