8O AN INTRODUCTION TO ENTOMOLOGY. 



they pair with their near relatives. The development of winged 

 sexual forms is therefore necessary in order to provide for inter- 

 crossing of individuals not closely related. Doubtless here as with 

 the true ants the winged males and females emerge from many nests 

 at the same time and mingle in a single swarm : in this way there is 

 opportunity for intercrossing. 



From the above it can be seen that among the Termites there 

 are four distinct castes : (i) Winged sexual forms or kings and 

 queens; (2) Wingless sexual forms or complemental males and 

 females ; (3) Workers ; (4) Soldiers. As both sexes are represented 

 in each caste, we have in all eight forms. 



There is space here for but little regarding the habits of these 

 wonderful insects. In the tropics certain species build nests of great 

 size. Some of these are mounds ten or twelve feet in height. Other 

 species build large globular masses upon the trunks or branches of 

 trees. All of the Termites are miners, and all avoid the light. 

 They therefore build covered ways from their nests to such places 

 as they wish to visit. In some of the hot countries they are the 

 worst of all pests. They will feed upon almost any organic matter ; 

 they destroy wooden structures of all kinds, including buildings and 

 furniture. Libraries are often completely ruined by them. In in- 

 festing anything composed of wood they usually eat out the interior, 

 leaving a thin film on the outside. Thus a table may appear to be 

 sound, but crumble to pieces beneath a slight weight ; entrance 

 having been made through the floor of the house and the legs of the 

 table. 



The mounds of Termites are composed chiefly of the excreted 

 undigested wood upon which the insects have fed.* This is moulded 

 into the desired form, and, on drying, it becomes solid. 



Like other Pseudoneuroptera, the Termites undergo an incom- 

 plete metamorphosis. The eggs as soon as they are deposited by 

 the queen are carried away by the workers to other chambers. The 

 young are fed upon prepared food, which is stored up in the form 

 of very hard and tough rounded masses, evidently composed of coin- 

 minuted wood. It is believed that the young Termites are also 

 fed on the sclerotia of some fungi. The young white-ants are ac- 

 tive; and all sizes, from the newly-hatched nymph to the full-grown 



* That this substance is composed largely of woody tissue is easily seen by a micro- 

 scopic examination; and I am informed by Prof. J. C. Branner, who has observed these 

 insects in Brazil, that he has seen the Termites eject the matter from the caudal opening 

 of the alimentary canal and add it to the nest or covered ways which they were building. 



