INTERRELATIONS OF INSECTS 



261 



sexual organs. With monstrous mandibles and head (Fig. 277, #), 

 their chief duty apparently is to defend the colony, though they fre- 

 quently fail to do so. 



The winged males and females (Fig. 277, (') which are sexually ma- 

 ture, swarm from the nest and mate. After the nuptial flight the pair 

 burrow into some crevice and shed the wings, which break off each along 

 a peculiar transverse suture, leaving four triangular stumps (Fig. 277, D). 

 The king and queen found a new colony and may live for several years, 

 sheltered in a special chamber, the queen, meanwhile, becoming enor- 

 mously distended (Fig. 278) with eggs and almost incapable of locomotion. 

 The prolificacy of the queen is astonishing; she can 

 lay thousands of eggs, sometimes at the rate of sixty 

 per minute. She is the nucleus of the colony, and 

 should she become incapacitated, is replaced by one 

 or more substitute queens, which have been developed 

 to meet the emergency; similarly, a substitute king is 

 matured upon occasion. These substitutes (Fig. 277,^) 

 differ from the primary pair in having nymphal wing- 

 pads in place of the remains of functional wings. 



These six kinds are by no means all that may occur 



/ *> 



in a single colony. Termcs lucifugus, according to 

 Grassi, has no less than fifteen kinds of individuals, 

 counting nymphs in various stages of development 

 toward workers, soldiers, and primary or else comple- 

 mentary, or reserve, kings or queens. 



Origin of Castes. Grassi maintains that all the 

 forms are alike at birth except as regards sex, and that 

 the differences between worker and soldier, which are 

 independent of sex, depend probably upon nutrition. 

 Grassi attributes all the diversities of caste, except 

 the sexual ones, to the character and amount of the food. 



Food. The food of termites is of six kinds: (i) wood; (2) matter 

 emitted from the oesophagus or rectum, termed respectively stomodaeal 

 and proctodceal food; (3) cast skins and other exuvial stuff; (4) the bodies 

 of their companions; (5) saliva; (6) water. Of these the proctodaeal 

 food is the favorite. Nymphs receive at first only saliva ; later they get 

 stomodseal and proctodseal food until, finally, they are able to eat wood 

 the staple food of a termite. 



American Species. Our common termite is Termcs Jlai'ipcs, which 

 occurs throughout the United States, excavating its galleries in decaying 



I'"K.. 278. Queen 

 of Ttrnits obesus. 

 Natural size. After 

 HAGEN. 



