68 FIRST BOOK OF ZOOLOGY. 



grasshopper. And yet these are all wings. In a similar way 

 do the mouth-parts of an insect vary. 



65. In the head of a mosquito, what appears to be a 

 single sting, by which the animal pierces the flesh and sucks 

 the blood, is in reality composed of long, delicate, thread- 

 like parts, which represent the mandibles, maxillae, and the 

 tongue, or ligula, which represents a prolongation of the 

 labium. In the bugs the mouth-parts are compacted into a 

 hard beak the piercer, so called, consisting of mandibles, 

 maxillae, and labium, the labrum being represented by an 

 acutely triangular piece. 



The mouth-parts of a beetle have already been described 

 in general terms. They are represented as separated from 

 the head in Fig. 68, while in Fig. 69 a side-view of another 

 beetle is given in which the mandible shows very promi- 

 nently, while the labrum, labium, and maxillae, do not show 

 at all, as they are concealed by the other parts. The maxil- 

 lary and labial palpi of one side are seen, however. 



66. In the butterfly the labial palpus is seen very large 

 and prominent, while the coiled, thread-like tongue represents 

 the pair of maxillae lengthened and joined, forming a long 

 elastic tube which can be coiled or uncoiled by the insect, 

 and through which it sips the nectar of flowers. In the 

 mouth-parts of a house-fly the parts are soft and fleshy, and 

 united together to form a sort of proboscis ; the maxillae are 

 minute ; the maxillary palpi are present as simple jointed ap- 

 pendages ; the mandibles are minute, and useless ; while the 

 labium is greatly developed, having a broad end which is 



