294 



ANIMAL STUDIES 



sharply edged, for cutting off bits of leaves and stems. 

 Those which take only liquid food, as the butterflies and 

 sucking-bugs, have their mouth parts modified to form a 

 slender, hollow sucking beak or proboscis, which can be 



thrust into a flower nectary, 

 pQ or into the green tissue of 

 plants or the flesh of animals, 

 to suck up nectar or plant sap 

 or blood, depending on the 

 special food habits of the in- 

 sect. The honey-bee has a 

 very complicated equipment 

 of mouth parts fitted for tak- 

 ing either solid food like pol- 

 len, or liquid food like the 

 nectar of flowers. The mos- 

 quito has a "bill" (Fig. 160) 

 composed of six sharp, slender 

 needles for piercing and lac- 

 erating the flesh, and a long 

 tubular under lip through 

 which the blood can flow into 

 the mouth. Some predaceous 

 insects, as the praying-horse 

 (Fig. 161), have their fore 

 legs developed into formidable 

 grasping organs for seizing and 

 holding their prey. 



256. Adaptation for self-de- 

 fense. For self-protection, car- 

 nivorous animals use the same 

 weapons to defend themselves 

 which serve to secure their 

 prey; but these as well as 

 other animals may protect themselves in other fashions. 

 Most of the hoofed animals are provided with horns, struc- 



FIG. 162. Acorns put into bark of tree 

 by the Californian woodpecker 

 (Melanerpes formicivorus bairdii). 

 From photograph, Stanford Uni- 

 versity, California. 



