INSECT COMMUNITIES 305 



to turn out unsatisfactorily are killed and eaten by their 

 nurses. Be this as it may, the fact remains that from 

 eggs which are apparently identical termites can produce 

 at will royalties, workers, soldiers, or any of the inter- 

 mediate forms which are found in the nest. Moreover, 

 the development of some females of the special sexual 

 forms is arrested, so that they neither produce wings nor 

 join in the swarming exodus ; but they are held in reserve 

 in case the reigning queen of the nest should die, when 

 one of them is promoted to take her place. These indi- 

 viduals have been called " complementary reserve queens," 

 and, when actually substituted for a queen, " substitution 

 queens." Male insects, or kings, appear to be reserved 

 in the same way. 



Some termites are far less advanced in their social 

 organisation than others. The yellow-necked species 

 (Caloiermes jlavicollls) of the Mediterranean littoral is, 

 according to Dr. Sharp, " a representative of a large series 

 of species in which the peculiarities of termite life are 

 exhibited in a comparatively simple manner. There is no 

 special caste of workers ; consequently such work as is 

 done is carried on by other members of the community, 

 viz. soldiers and the young and adolescent. . . . The king 

 and queen move about, and their family increases but 

 slowly. After fifteen months of their union they may be 

 surrounded by fifteen or twenty young ; in another twelve 

 months the number may have increased to fifty, and by 

 the time it has reached some five hundred or upward the 

 increase ceases. This is due to the fact that the fertility 

 of the queen is at first progressive, but ceases to be so. 

 A queen three or four years old produces at the time 

 of maximum production four to six eggs a day. When 

 the community is small — during its first two years — the 

 winged individuals that depart from it are about eight 



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