A cigar box and a bottle with a notched cork may be used for holding specimens. Cigar boxes may be used for holding collections of dried insects. Cork or ribbed packing paper may be fixed in the bottom for supporting the insect pins. Moth balls or tobacco may be placed in each box to keep out the insect pests which infest collections. It is pleasant and profitable to take to the fields a small book like this one, or even Comstock’s “Manual of Insects,” or Kellogg’s “American Insects,” and study the insects and their habits where they are found. Captured insects which, in either the larval or perfect stage, are injurious to vegetation, should always be killed after studying their actions and external features, even if the internal structure is not to be studied. Beneficial insects, such as ladybugs, ichneumon flies, bees, mantis (devil’s horse), dragon flies, etc., should be set free uninjured. ANATOMY AND GENERAL CHARACTERISTICS OF THE CLASS INSECTA The =body= of an insect (_e.g._ a wasp, Fig. 122) is divided by means of two marked narrowings into three parts: the head (_K_), chest (_B_), and abdomen (_H_). [Illustration: FIG. 122.--A WASP.] The =head= is a freely movable capsule bearing four pairs of appendages. Hence it is regarded as having been formed by the union of four rings, since the _ancestor of the insects_ is believed to have consisted of similar rings, each ring bearing a pair of unspecialized legs. The early grub or caterpillar stage of insects is believed to resemble somewhat the ancestral form. The typical =mouth parts= of an insect (Fig. 123), named in order from above, are (1) an upper lip (labrum, _ol_) (2) a pair of biting jaws (mandibles, _ok_) (3) a pair of grasping jaws (maxillæ, _A_, _B_), and (4) a lower lip (labium, _m_, _a_, _b_). The grasping jaws bear two pairs of jointed jaw fingers (maxillary palpi, _D_, _C_), and the lower lip bears a pair of similar lip fingers (labial palpi, _d_). The biting jaws move sideways; they usually have several pointed notches which serve as teeth. Why should the grasping jaws be beneath the chewing jaws? Why is it better for the lower lip to have fingers than the upper lip? Why are the fingers (or palpi) jointed? (Watch a grasshopper or beetle eating.) Why does an insect need grasping jaws? [Illustration: FIG. 123.--MOUTH PARTS OF BEETLE.] [Illustration: FIG. 124.--EXTERNAL PARTS OF A BEETLE.] The chest, or =thorax=, consists of three rings (Fig. 124) called the front thorax (prothorax), middle thorax (mesothorax) and hind thorax (metathorax), or first, second, and third rings. The first ring bears the first pair of legs, the second ring bears the second pair of legs and the upper or front wings, and the third ring bears the third pair of legs and the under or hind wings. [Illustration: FIG. 125.--LEG OF INSECT.]