WONDERFUL TEETH AND TONGUES 243 



presents the tongue of butterflies generally, and is 

 the organ which, when unrolled, seeks and gathers 

 the sweet nectar or honey from the flower-blooms 

 of summer. The small projections observed at 

 the tip of the proboscis are generally supposed to 

 be organs of taste, to aid in sampling the various 

 drinks produced so abundantly by the flowers or 

 the ripe fruits of our gardens. The thickness of 

 this sucking-tube may be estimated roughly as 

 about the same as a fine horsehair. It consists of 

 two complex tubes side by side, capable of being- 

 separated and joined again at the insect's pleasure. 

 The tubes are so firmly and perfectly united by 

 minute hairs or bristles as to make an air-tight 

 surface; the two tubes then acting as one. 



Those of my readers who when "sugaring" for 

 moths have had their " sugar" visited by the largest 

 British beetle, known familiarly as the stag-beetle, 

 and have seen, and possibly felt, its conspicuous 

 mandibles, would probably imagine it to be a most 

 predacious insect. However, its food is simply the 

 juice of plants. Its horny and formidable man- 

 dibles serve only to wound the plant and so produce 

 a flow of juice or sap for it to suck up with its 

 double brush-like tongue, which may be seen in 

 the centre of its mouth organs. Fig. 163 shows 

 a portion of the mouth organs dissected out with 

 this sap-sweeping tongue in the centre. 



