SENSES OF INSECTS. 213 
can dart to the region of the stars, and convey by the 
perceiving sense, to the sensory, ideas of innumerable 
objects. Next in rank is hearing, which can receive 
sounds from a great distance; but the ideas it remits are 
confined only to one object, the variations of tones. In 
the other organs the sensitive power is much more con- 
fined. There is another difference between the intel- 
lectual and physical senses : — the former are the only 
ones that receive and convey sensations of the beautiful 
and sublime; of harmony and discord, — the latter, though 
they minister more to our sensual enjoyments, add 
little to our intellectual ; and therefore too devoted an 
indulgence in them debases our nature, and levels us 
with the brutes, which use their eyes and ears only for 
information, not for pleasure 1 . 
In man the ordinary five senses are usually in their 
greatest perfection, although in some animals particular 
senses have a greater range. The Vertebrates in general 
are also gifted with the same number, though there are 
some exceptions. But in the Invertebrates they are sel- 
dom to be met with all together in the same object. The 
Cephalopods have no smell. Several Gasteropods can 
neither hear nor see. The animals of bivalve shells have 
neither eyes, nor ears, nor smell; and the zoophytes and 
the races below them have, it is affirmed, only the single 
sense of touch, which in them is so extremely delicate as 
to be acted upon even by light b _ 
Not so our insects. These, there is good reason to 
a N. Diet. d'Hist. Nat. xxx. 584—. 
,J Cuv. Anat. Comp. ii. 362, 
R 2 
