BUCCAL APPARATUS OF INSECTS. 99 



and the tongue. Sometimes this proboscis acquires an enormous 

 length (Fig. 421): sometimes on the contrary it is hardly visi- 

 ble. Lastly, among the Butterflies, which are also supported 

 on liquid substances, but which find them at the bottom of the 



flowers, and there- 



6 ^BESKSK fore have no occa- 



sion for instruments 

 to procure them, 



d Txi$P yU^i^^B^V there exist no se&e 



performing the func- 

 tions of lancets, as 

 among the preced- 

 ing ; and the mouth 



; a, head ; \^SiS8llai S^aF long tubular trunk, 



6, base of antennae; c, ^"^^CjjBgSSKfiSr -i j ^ i 



eye; d, trunk; e, ^^^^S COlled into a Spiral, 



palpi. FIG. 423. MORPHO HKLKNOR. an( J composed of tWO 



slender filaments, each channelled on its internal edge, so that a 

 tube is formed by the adhesion of the two ; these are nothing 

 else than the maxillae very greatly lengthened and modified in 

 their form. At the base of this tube is seen a small membranous 

 piece, which is the representative of the labrum ; and on each 

 side of this, a small tubercle, the only vestige of the mandibles. 

 We also perceive the rudiments of the maxillary palpi ; and be- 

 hind is found a small triangular labium, having two very large 

 labial palpi, composed of three joints, and nearly always clothed 

 with scales. 



675. The alimentary canal generally presents a very com- 

 plicated structure : sometimes it is straight, and has very nearly 

 the same diameter throughout its entire length ; but usually it 

 is more or less convoluted, and has several successive enlarge- 

 ments, and contractions. We may distinguish in it (Fig. 424), 

 a pharynx (), an oesophagus (b\ a first stomach or crop (c), a 

 second stomach or gizzard (d), of which the walls are muscular 

 and often armed with horny pieces fitted to triturate the food ; 

 a third or true digestive stomach (e\ whose texture is soft and 

 delicate ; a small intestine (/), a coecum, and a rectum (g). As 



