SYSTEM OF NATURE 
83 
larity in the means provided for the attainment of these 
ends is to be anticipated; but those authors appear to me far 
too imaginative who fix the site of a faculty without tole¬ 
rably strong evidence of their conclusions being just. We 
see that a butterfly and a swallow are furnished with im¬ 
plements adapted for rapid progression through the air. 
In both instances we call these implements wings, a name 
so sanctioned by usage that it would be futile to attempt 
to alter it in either instance. If, however, we carefully 
investigate this subject,— if we endeavour to trace out the 
identity of these so-called wings, we shall find the matter 
one of infinite difficulty ; and I would rather undertake to 
prove an identity between the lungs of the swallow and 
the wings of the butterfly, or between the ribs of the 
swallow and the legs of the butterfly, than between the 
same parts of the two animals. The same remark applies 
still more forcibly to the senses of sight, smell and hearing, 
all of which have been located in every possible part of 
an insect’s head. Our most distinguished British entomo¬ 
logist, Mr. Kirby, fixes the nose of a beetle where he finds 
that organ on the human face, and some authors of less 
celebrity have dignified the antennae by the name of ears, 
while others strenuously contend that they perform the 
office of eyes or nose; but —quicquid ex phenomenis non 
deducitur hypothesis vocanda est — I consider all such 
nomenclature as this, hypothesis of the worst and most 
injurious kind. I would even go so far as to say that I 
consider the universally accepted terms of wings, legs and 
arms in insects, spiders and cephalopods, as metaphorical, 
and to be received only as indicating a similarity of em¬ 
ploy. The more closely we investigate the subject and en¬ 
quire into its various bearings, the more thoroughly shall we 
