260 



COMPARATIVE ZOOLOGY 



tribe, we have a transition between the biting and the 

 sucking insects the mandibles "supply the place of 

 trowels, spades, pickaxes, saws, scissors, and knives," 

 while the maxillae are developed into a sheath to inclose 

 the long, slender, hairy tongue which laps up the sweets 

 of flowers. In the suctorial butterfly, the lips, mandi- 

 bles, and palpi are reduced to rudiments, while the 



maxillae are excessively 

 lengthened into a proboscis, 

 their edges locking by means 



FIG. 220. Head of a Wild Bee (An- 

 thophora retusa), magnified, front 

 view: a, compound eyes; b, 

 clypeus; c, three simple eyes; d, 

 antennae; <?, labrum; f, mandibles; 

 z, maxillae; h, maxillary palpi; /, 

 palpifer; /, labial palpi; m, para- 

 glossae; k, ligula. 



FIG. 221. Proboscis of a Butterfly, magnified. 



of minute teeth, so as to form 

 a central canal, through which 

 the liquid food is pumped up 

 into the mouth. Seen under 

 the microscope, the proboscis is made up of innumerable 

 rings interlaced with spiral muscular fibers. The probos- 

 cis of the fly is a modified lower lip ; that of the bugs and 

 mosquitoes, fitted both for piercing and suction, is formed 

 by the union of four bristles, which are the mandibles 

 and maxillae strangely altered, and encased in the labium 

 when not in use. 



