HOW ANIMALS EAT. 



59 



the Bee tribe, we have a transi- 

 tion between the biting and the 

 sneking Insects — the mandibles 

 "supply the place of trowels, 

 spades, pickaxes, saws, scissors, 

 and knives," while the maxillae 

 are developed into a sheath to 

 enclose the long, slender, haiiy 

 tongue which laps up the sweets 

 of flowers. In tlie suctorial But- 

 terfly, the lips, mandibles, and 

 palpi are reduced to rudiments, 

 while the maxillae are the only 

 useful oral organs. These are 

 excessively lengthened into a 

 proboscis, their edges locking ria- 22.— Head of a wuu aae {An- 



, . , tluyphffra retuna), frout view: a, 



by means 01 mmute teeth, so as compouiid eyes; 6, ciypeiis; c, 



• £ ' - 1 ! i.1 1 three simple eyes; d, anteDiise; e, 



to form a central canal, through 1,,^™™ ; /, macditiiesi i,maxiii«; 

 which the liquid food is pumped J^™"^"'"'? p"'?': '. paipifen 3 



^ r r labial palpi ; m, paraglossse ; A:, 



up into the mouth. Seen un- ligo'a- 

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

 able rings interlaced with spiral muscular fibres. Tlie 



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 

 maxillae strangely al- 

 tered, and encased in 

 the labium wlien not 



Fig. 23.— Proboscis uf a Butterfly, mni'nifled. in USC. 



