Anatomy of Insects. 43 



CHAPTEE II. 



ANATOMY AND PHYSIOLOGY. 



In this chapter I shall give first the general anatomy of in- 

 sects ; then the anatomy, and still more wonderful physiology, 

 of the honey-bee. 



ANATOMY OF INSECTS. 



In all insects the body is divided into three well-marked 

 portions (Fig. 2.); the head (Figs. 4 and 5), which con- 

 tains the mouth-organs, the eyes, both the compound and when 

 present the simple, and the antennae ; the thorax, which is 

 composed of three rings, and gives support to the one or two 

 pairs of wings when present, and to the three pairs of legs ; 

 and the abdomen, which is composed of a variable number of 

 rings, and gives support to the external sex-organs, and when 

 present to the sting. Within the thorax there are little more 

 than muscles, as the concentrated strength of insects, which en- 

 ables them to fly with such rapidity, dwells in this confined 

 space. Within the abdomen, on the other hand, are the sex- 

 organs, by far the greater and more important portions of the 

 alimentary canal, and other important organs. 



ORGANS OP THE HEAD. 



Of these the mouth organs (Fig. 7) are most prominent. 

 These consist of an upper lip — ^labrum, and under lip — labium, 

 and two pairs ot jaws 'which move sidewise ; the stronger, horny 

 jaws are called mandibles, and the more membranous, but 

 usually . longer, maxiUse. The labrum (Fig. 7, t) is well de- 

 scribed in the name upper lip. It is attached, usually, by a 

 movable joint to a similarly shaped piece above it, called the 

 clypeus (Fig. 7, c), and this latter to the broad epicranium 

 (Fig. 7, o), which contains theantennse, the compound, and, 

 when present, the simple eyes. 



The labium (Fig. 17) is not described by the name under- 

 lip, as its base forms the floor of the mouth and its tip the 

 tongue. The base is usually broad, and is called the men- 

 tum, and from this extends the tongue (Fig. 17, a) or ligula. 



