2o6 THE FOOD OF ANIMALS 



sort of lappet. Whether the ligula, often called the tongue, is 

 really part of the second maxillae or a special structure is not 

 definitely known. When in use the proboscis is extended, and 

 then thrust into the nectar- containing organ, the sweet fluid 

 passing up into the mouth partly by capillary attraction and 

 partly by some kind of suctorial action. Within the body the 

 nectar passes into a region of the digestive tract known as the 

 crop or honey -bag, from which it is later on returned into one 

 of the waxen cells of the comb, having undergone chemical 

 changes (probably brought about by the saliva), converting it 

 into honey. 



Different species of bee differ very much among themselves 

 in the extent to which the proboscis is specialized ; in the so-called 

 short-tongtied bees, for example, this organ is comparatively broad 

 and short, while in some forms it may even be longer than in the 

 honey-bee, as, for instance, in the species of Euglossa (a tropical 

 American genus), where it may be of greater length than the 

 insect's body. 



Wasps possess mouth-parts resembling those of the less- 

 modified Bees. The adults feed for the most part on nectar 

 and fruit-pulp, and the young larvae are fed in their early stages 

 on similar food, though later on they are commonly provided 

 with animal nourishment. 



Ants take place in the very first rank among Insects as 

 regards structure, intelligence, and specialization of habit, their 

 communities in many species being organized in the most won- 

 derful manner. The food largely consists of nectar and other 

 vegetable substances. The mouth-parts include the usual struc- 

 tures, the most interesting peculiarity being found in the large 

 -mandibles, which possess an unusual power of free movement, 

 and project externally to the other pairs of jaws. The reason 

 for this is to be sought in the varied industrial uses to which 

 they are applied in the economy of the nest. 



Certain species of Ant are so fond of nectar that they are 

 termed Honey-Ants, which name is applied to species belonging 

 to very different genera native to Mexico and the United States 

 [Myrmecocysttis) (fig. 440), South Africa {Plagiolepis), and Aus- 

 tralia [Melophorus). Taking the American forms in illustration 

 it is found that some of the workers gorge themselves to excess 

 on nectar produced by a small oak-leaf gall, so that the abdomen 



