Anatomy of Insects, ei 



CHAPTER II. 

 Anatomy and Physiology. 



In this chaptei" I shall give first the general anatomy of 

 insects; then the anatomy, and still more wonderful physi- 

 ology, of the honey bee. 



ANATOMY OF INSECTS. 



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

 portions (Fig. 2.) ; the head (Figs. 5 and 6), which con- 

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

 when present, the simple, and the antennas; 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 exter- 

 nal sex organs, and when present, to the sting. Within 

 the thorax there are little more than muscles, as the con- 

 centrated strength of insects, which enables them to fly 

 with such rapiditj', dwells in this confined space. Within 

 the abdomen, on tlie other hand, are the sex organs, by far 

 the greater and more important portions of the alimentary 

 canal, and other important organs. 



ORGANS OF THE HEAD. 



Of these the mouth organs (Fig. 8) are most prom- 

 inent. These consist of an upper lip — labrum, and under 

 lip — labium, and two pairs of jaws which move sidewise; 

 the stronger, horny jaws are called mandibles, and the 

 more membranous, but usually longer, are named maxillse. 

 The labrum (Fig. 8, /) is well described in the name upper 

 lip. It is attached, usually, by a movable joint to a simi- 

 larly shaped piece above it, called the clypeus (Fig. 8, c), 

 and this latter to the broad epicranium (Fig. 8, o) which 

 contains the antennffi, the compound, and, when present, 

 the simple eyes (Fig. 5). 



The labium (Fig. 35) is not described by the name 

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



