102 Objects for the Microscope. 



of the Pentamera, by its long slender eleven-jointed antennse 

 of the same thickness throughout. 



Next examine the curious hatchet-shaped joint at the 

 end of the palpi small feelers attached to the jaws, 

 and which are very important points for observation, as 

 their number and shape determine the species of many 

 beetles. 



We now see the various parts of the mouth the labrum 

 or lip notched in front ; the two hairy maxillce formed of 

 five pieces delicately fringed, and used for cleansing the 

 food ; two strong mandibles or jaws for seizing their prey. 



Two compound eyes which, in the male, occupy nearly 

 the whole of the head. 



The thorax, or body, to which are attached the three 

 pairs of legs, and the wings and wing-cases. 



This thorax is a wonderful piece of mechanism. It 

 cannot be so well seen in this slide, because the elytra or 

 wing-cases partly cover it ; but it should be carefully studied 

 in various specimens. There are three chief parts 



The pro-thorax ; the segment nearest the heart, and 

 supporting the first pair of legs. 



The meso-thorax : bearing the elytra, or wing-cases, and 

 the middle pair of legs. 



The meta-thorax ; bearing the wings and the last pair of 

 legs. 



But these are again composed of no less than twenty- 

 two smaller pieces, equally distinct and present in the thorax 

 of the tiniest beetle ; and if we consider the complicated 

 machinery necessary for the direction and control of all the 

 muscles required for insect locomotion, the care bestowed 

 upon the formation of the thorax will be at once accounted 

 for. The movement of the legs in running, creeping, 

 climbing, swimming, fighting, seizing their prey, cleansing 

 their bodies, and the varied motions of the wings and 

 wing-cases these all demand distinct muscles and points 

 of attachment. The whole cavity of the thorax is occupied 

 by the wing and leg muscles, and the great ganglion of 

 nerve which directs them as a viceregent from the seat of 

 sensation, the head. 



