parts of insects. 
27 
tfict, such an organ may be regarded as that of smell. Should the an 
tcnna present a tissue of many nerves, what inconvenience can result 
‘™ Opposing that this tissue is capable of transmitting odour ? 
°uld not this hypothesis, on the contrary, be more simple and more 
consonant to anatomical principles, than that which fixes the seat of 
stmell at the entrance of the stigmata? Besides, this last mode of ex- 
planation will not, I presume, suit the crustaceous animals, which so 
nearly approach to insects. 
“ -■ Many mule insects have their antenna- more developed than the 
females ; a fact easily explained, if we admit that these organs are the 
scat of smell. 
“ 3. It is certain that most of those insects which live or deposit 
their eggs on putrid animal or vegetable matters, stagnant waters, or 
any substance, in short, which, for a time, affects peculiar localities, 
are almost uniformly distinguished by a greater development of the an- 
tennte. Such, for example, are the Scarabmus, Dermestes, Silpha, Clerus, 
Tenebrio, 'Tipda, Bibio, Ac. These require a more perfect sense of 
smell, and are organized accordingly. 
“ 4. A great many insects which are entirely predaceous have simple 
antenna; ; and those which arc characterized by similar manners, and 
which are sedentary, have none at all ; as, for instance, the Atari, and 
a considerable portion of Lamarck’s Arachnidie. 
“ 5. Insects discover then- habitation and food by the sense of smell. 
I have deprived several insects of their antenna?, when they instantly 
fell into a state of stupor or derangement, and seemed to lie incapable 
of recognising their haunts or their food, though just beside them. 
Such experiments deserve to he prosecuted. I would recommend, for 
example, the varnishiug or covering the antennae of dung beetles, and 
placing them near animal excrements, of which they are particularly 
fond, to observe if they would repair to them as usual. 
“ 6 - The nerves terminate at tire antenna?; and their articulations, 
though externally covered with a pretty thick membrane, are hollow, 
lined within by a soft substance, which is often of a watery consist- 
ency, and whose extremity, when opposed to the air, may receive its 
impressions.” 
Os, the Mouth. In order to afford some idea of the amazing dif- 
< rence that prevails in the structure of the several parts or organs 
which constitute tire mouth, it will lie only requisite to observe, that 
t , ? classification of all insects in the Pabrician system Ls founded on 
sists • arac . ter - There are ten principal parts of which the mouth con- 
1 , •! ’ aiM ' ' l ls from the relative proportion of each, from the dissimi- 
an y nr the fonn, position, variation in number, or occasional pecu- 
. antics, that the most permanent characters are deduced. These parts 
are one disadvantage; they are generally small, and from this cir- 
cumstance have not been so universally adopted in the arrangement 
