184 



THE STUDY OF INSECTS 



Fig. 324. — Maxillae of cotton-moth, and tip of same enlarged. 



Fig. 325. — Cross-section of maxillae. 



there will be found a long sucking tube, which when not in use is coiled 

 on the lower side of the head between two forward-projecting appendages. 

 This long sucking tube is composed of the two maxillae, greatly elongated, 



and fastened together side by 

 side. In Figure 324 there is 

 represented a side view of the 

 maxillae of a moth; and in 

 Figure 325 a cross-section of 

 these organs. Each maxilla is 

 furnished with a groove, and 

 the two maxillae are so fastened 

 together that the tw r o grooves 

 form a tube through which 

 the liquid food is sucked. As 

 a rule the maxillae of insects 

 of this order are merely fitted 

 for extracting the nectar from 

 flow r ers, but sometimes the tips 

 of the maxillae are armed with 

 spines, as shown in Figure 324. 

 This enables the insect to 

 lacerate the tissue of ripe fruits 

 and thus set free the juice, 

 which is then sucked up. 

 Many moths do not eat in 

 the adult state ; with these the 

 maxillae are wanting. The two forward projecting organs between which the 

 maxillae are coiled when present are 

 the labial palpi. In some moths the 

 maxillary palpi are also developed. 

 The larvae of Lepidoptera are 

 known as caterpillars. They vary 

 greatly in form and appearance; 

 but are usually cylindrical, and pro- 

 vided with from ten to sixteen legs, 

 — six thoracic legs, and from four 

 to ten abdominal legs. The thoracic 

 legs, which are finally developed 

 into the legs of the adult, have a 

 hard external skeleton; and are 

 jointed, tapering, and armed at the 

 end with a little claw. The abdom- 

 inal legs, which are shed 

 with the last larval skin, 

 are thick, fleshy, without 

 joints, elastic or contrac- 

 tile, and are generally 

 furnished at the extrem- 

 ity with numerous, min- 

 ute hooks (Fig. 326); they are termed prologs. 



Most caterpillars, except the larvae of nearly all butterflies, spin 

 cocoons (Fig. 327). In some instances, as in case of the silkworms, a 



Fig. 326. — Larva of a hawk-moth. 



