CLASS INSECTS. 



419 



between the limbs. Its length is sometimes so considerable 

 that it passes backwards beyond the posterior extremity of 

 the abdomen. 



In the flies the proboscis, sometimes soft and retractile, 

 sometimes horny and elongated, represents also the lower lip, 

 and often carries feelers on its basis ; a longitudinal groove 

 occupies the superior surface and lodges the stylets, whose 

 number varies from two to six, and whose analogues in the 

 bruising or grinding insects are the mandibles, the jaws, 

 and the languette or little tongue. Sometimes this proboscis 

 acquires an enormous length (Fig. 440), sometimes, on the 

 contrary, it is scarcely visible. 



Fig. 441 .Proboscis 

 of a Butterfly.* 



Fig. 442. Morpha Helenor 

 ( Vampa) . 



524. Finally, in the butterflies (Fig. 424), which are 

 also nourished on liquid substances, but which are found at 

 the bottom of flowers, and which have no occasion for 

 cutting or piercing instruments to obtain them, there no 

 longer exist stylets performing the functions of lancets, as in 

 the preceding, and the mouth is furnished with a long pro- 

 boscis (c d, Fig. 441), rolled into a spiral, and composed of 

 two filaments, hollowed into a groove on their inner surface, 

 which are nothing but jaws extremely elongated and modi- 



* a, head j &, base of the antennae or feelers ; c, the eye ; d, the pro'/oscis j 

 e t palpi. 



E E 2 



