-6 ORGANS OF SUPPORT, 



are so small, indistinct, and anchylosed together, that 

 entomologists are not agreed as to their number, some 

 considering this part as composed of one segment, some of 

 three, and others of seven segments consolidated together. 

 The head, (Fig. 1 6. g,) supports the organs of mastication and 

 of the senses, and contains internally the parts of the mouth, 

 the pharynx, the commencement of the oesophagus, and 

 the two first pairs of ganglia. We observe attached to the 

 head an inferior lip, or labium, with its jointed pal^n 

 (Fig. 16. ,) and a superior lip or labrum, both of which 

 extend transversely across the axis of the body, a pair 

 of mandibles without palpi, and a pair of maxillae pro- 

 vided with these jointed organs of sense. The head 

 supports also a single pair of articulated antenna (Fig. 1 6. 

 e,) most variable in form, a lingua, and a pair of eyes 

 (Fig. 16. /,) generally compound, with three simple 

 ocelli. 



The thorax supports the legs arid the wings, and is 

 composed of three segments, the anterior of which (Fig. 

 16. h } ) is termed prothorax, the second mesothorax (Fig. 

 16, m,) and the third metathorax (Fig. 16. o.) The pro- 

 thorax supports the first pair of legs, the mesothorax 

 the second pair of legs, and the first pair of wings, 

 and the metathorax has attached to it the third pair of 

 legs, and the second pair of wings. These segments of 

 the thorax, like vertebrae, are composed of several ele- 

 ments which send processes inwards for the attachment 

 of muscles, and the protection of the contained organs, 

 and each of the segments exhibits a development pro- 

 portioned to that of the parts it supports or contains. 

 The parts of the legs have received names taken from 

 those of the locomotive organs of vertebrata. Each leg 

 is attached to its corresponding segment by a short, 

 round, moveable articulation, called the coxa, or haunch 

 (Fig. 16. m ; ) to this succeeds the trochanter (Fig. 16, i,) 

 which is likewise a very short joint, and less moveable. 

 The femur (Fig. 16. &,) is a strong and lengthened ar- 

 ticulation, commonly extended horizontally, and the tibia 

 (/,) which succeeds it is generally the most lengthened 

 and slender joint of the leg, and directed vertically. The 

 little joints of the tarsus (Fig. 16. A, B, C,) which follow, 



