HOW ANIMALS EAT. 



50 



the Bee tribe, we have a transi- 

 tion between the biting and the 

 sucking Insects — the mandibles 

 "supply the place of trowels, 

 spades, pickaxes, saws, scissors, 

 and knives," while the maxilte 

 are developed into a sheath to 

 enclose the long, slender, hairy 

 tongue which laps up the sweets 

 of flowers. In the suctorial But- 

 terfly, the lips, mandibles, and 

 palpi are reduced to rudiments, 

 while the maxilte are the only 

 useful oral organs. These are 

 excessively lengthened into a 

 proboscis, their edges locking 

 by means of minute teeth, so as 

 to form a central canal, through 

 which the liquid food is pumped 

 up into the mouth. Seen un- 

 der the microscope, the proboscis is made up of innumer- 

 able rings interlaced with spiral muscular fibres. The 



proboscis of the Fly 

 is a modified lower 

 lip ; that of the Bugs 

 and Mosquitos, fitted 

 both for piercing and 

 suction, is formed by 

 the union of four 

 bristles, which are 

 the mandibles and 

 maxilte strangely al- 

 tered, and encased in 

 the labium when not 



Fig. 23.— Proboscis of a Butterfly. in USC 



Fig. 22.— Head of a Wild Bee (in- 

 thophora retusa), front view: a, 

 compound eyes; b, clypeus; c, 

 three simple eyes ; d, antennae ; 

 labrnm : /, mandibles ; i, maxillae ; 

 h, maxillary palpi; l y palpifer; j, 

 labial palpi ; m, paraglossae ; k, 

 ligula. 



