258 



PTILOTA : IMAGO EXTERNAL ANATOMY. 



of the internal organ, wliieli, from analogy, may be termed 

 the lingua, or tongue, and which is very distinct in many 

 orthopterous, and some neuropterous, insects, in which 

 orders the general structure of the labium, and its various 

 parts, is very similar to that of the beetles, except that in 

 the former, the ])art to which I have restricted the term 

 labium, or ligula, is divided longitudinally into four branches. 



Figs. Ill, Labium of Geotnipes— 112, ditto of Melolontha— 113, ditto of Citindela— 

 114, ditto of Gryllus outside— 115, ditto laterally. 



In the Hymenoptera, however, the labium has reached its 

 fullest developement ; and this is more especially the case in 

 the bee tribes, to which (without going through the other 

 hymenopterous families) it will be advantageous to direct 

 om" attention. I have said that in these tribes the maxillae 

 co-operate v^ith the labium, in order to enable the insect to 

 suck the nectar of flowers. The machinery by which the 

 lower parts of the bee's mouth (to which, from analogy, the 

 term tongue is often, but not very correctly, applied) are 

 protruded, is exceedingly beautiful. On referring to the 

 figures given of the mouth of the bee in various states, 

 in a subsequent page, the maxillae and their very minute 

 palpi will be observed to be extended on each side of the 

 central piece, which, it will be seen, arises from a short tri- 



