250 SENSES OF INSECTS. 
the spiracles are organs of smell as well as of respiration. 
Lehmann has adduced several arguments in support of 
this opinion. Because we both respire and smell with 
our nostrils, he concludes that neither the antennee nor 
any other part of the head of insects can serve for smell, 
since they are not the seat also of respiration; and that 
there can be no smell where the air is not inspired. 
Again, because nerves from the ganglions of the spinal 
chord terminate in bronchiz near the spiracles, they 
must be for receiving scents from those openings. Though 
it was necessary, in the higher animals, that the organ of 
scent should be near the mouth, because they are larger 
than their food; yet the reverse of this being the case 
with insects, which often even reside in what they eat, it 
is to them of no importance where their sense of smelling 
resides’. By exposing antennee, by means of an orifice 
in a glass vessel, to the action of stimulant odours, they 
appeared quite insensible to it: but he does not name 
the result of any experiment in which he exposed the 
mouth to this action; nor at all distinctly how the insect 
was affected when the spiracles were exposed to it°. 
But though some of these arguments appear weighty, 
there are others, I think, that will more than counterba- 
lance them, making it probable that the seat of this sense 
is in the head, either in its ordinary station at the extre- 
mity of what I call the xose, between it and the upper-lip, 
or under those parts. That the nose corresponds with 
the so-named part in Mammalia, both from its situation 
and often from its form, must be evident to every one 
who looks at an insect¢; and when we further consider 
* Lehmann De Usu Antenn. ii. 28. 5 Thid. 31. 
© Thid. 35—. 4 Vox. IIT. p. 475—. 
