CLASS INSECTA. 



denomination of mandibles ; the two others alone have pre- 

 served that of jaws. They have, moreover, one or two arti- 

 culated threads, which are called palpi or antennulcB^ a cha- 

 racter which, in this class, the mandibles never exhibit. 

 Their extremity is often terminated by two divisions or 

 lobes, the exterior of which is named, in the orthoptera (in 

 French), galHe {galea, Fabr.). We have already mentioned 

 that the upper lip is termed lahrum ; the other, or the lip 

 properly so called {labium) is composed of two parts. The 

 more solid and under part is the chin {mentum) ; the upper, 

 which very frequently has two palpi, is the tongue {lin- 

 gua)* 



In the sucking insects, or those which take nothing but 

 fluid aliment, these divers organs of manducation present 

 themselves under two sorts of general modifications. In the 

 first the mandibles and jaws are replaced by small laminae, 

 formed like blades or lancets, composing, by their union, a 

 sort of sucker, which is received into a sheath, the substitute 

 for a lip, either cylindrical or conical, and articulated in the 



* See what we have said on this subject, in the generalities which pre- 

 cede the particular account of each class. The lower lip appears to us to be 

 but a particular modification of the second jaws of the decapode Crusta- 

 cea combined with their tongue. The changes which these parts gra- 

 dually undergo in the Crustacea, the arachnida and the myriapoda, would 

 lead us to believe it ; on this hypothesis, the six thoracic feet would be the 

 analogues of the jaw-feet, and this has been already recognized in relation 

 to the Crustacea of the genus aptis. Then the first five segments of the 

 abdomen in the hexapod insects, would represent those to which in the 

 decapode Crustacea, are attached the feet, properly so called, or the third 

 and fourth following ones of the amphipod and isopod Crustacea. All 

 the researches which have been published on the thorax of insects, though 

 otherwise very useful and laudable, will necessarily undergo essential 

 alterations, when naturalists come to compare this part of the body in 

 the three classes of articulated animals with articulated feet. Nomen- 

 clature is very far from being fixed in this particular. 



