8 BEETLES. 



give space to the numerous sense-organs located in them, the feel- 

 ers, usually composed of eleven joints, are either lengthened out 

 very much , are feather-like, or are like the leaves in a book, and 

 in this manner have the entire surface greatly enlarged. The form 

 of the feeler serves to a great extent as a basis for classification, 

 hence its different shapes have received special names, as may be 

 seen by consulting the illustrations. 



Like other insects, beetles possess a thorax composed of three 

 pieces, closely soldered together (Fig. 5). In most insects the sur- 

 face of all three pieces can be seen from above ; in beetles, how- 

 ever, only the anterior piece, the usually broad pro-thorax, is visi- 

 ble on the back. The two other pieces are hidden below, with the 

 exception of a small wedge-shaped piece, a section of the meso- 

 thorax, which is termed the scutellum. This is, in most cases, 

 plainly visible where the sutures of the elytra join near the pos- 

 terior margin of the pro-thorax. A study of the illustrations will 

 explain the anatomy better than a mere description. The abdomen 

 joins the thorax by a wide base; the former is in many cases en- 

 tirely hiddoi and protected by the wing-covers, hence is rather 

 soft. But whenever these wing-covers are short, then the sur- 

 face of the abdomen not covered by them is hard and horny, as it 

 always is on the miprotected lower surface. When not covered, 

 the abdomen is not only soft, but also light in color; all exposed 

 parts are darker, and frequently beautified with markings of vari- 

 ous colors and patterns. 



Besides the wings already mentioned the adult beetles have 

 as organs of locomotion six legs, which vary greatly in size and 

 shape, as may be seen in Fig. 10. Beetles which live in water have 

 them adapted for swimmmg; those that have to run about in 

 search of other insects possess very long legs to enable them to 

 catch their prey. Others again, which live upon plants, have 

 their legs arranged to hold on as tightly as possible, so as not to be 

 blown down by even a heavy wind, and still others, which hide in 

 the ground, have at least their front legs so arranged that they 

 can burrow with great ease. In fact, by looking at the legs of a 

 beetle the observer can soon judge what the habits of that insect 

 are. In most cases the legs are the principal organs of locomo- 

 tion, and only in a limited number of beetles are both legs and 



