32 Riley Presidential Address. 



on the one hand, and the Termites on the other, is that in the 

 latter the workers or neuters (including the soldiers) are not un 

 developed females, but consist of both sexes, and are in reality 

 arrested or modified larvae, in which the sexual organs are but im 

 perfectly developed or are completely atrophied. They are recog 

 nizable as neuters even after the first larval molt. The common 

 North American species, Termes flavipes, is doubtless familiar to 

 most of you. It occurs in vast numbers in rotten or prostrate logs, 

 and frequently invades our houses wherever there is wood in pro 

 cess of decay. The newly-hatched young are very tender and 

 helpless, and move but little, and while in the order Neuroptera 

 the young larva is usually able to care for itself immediately 

 after birth, the newly hatched Termite has become more or less 

 dependent upon the care of the workers, which either feed it with 

 partly digested food from their own mouths, or with their own 

 secretions, or else prepare food for it. The eggs are laid in large 

 numbers by fertile females or supplementary queens, but are car 

 ried long distances by the workers into chambers which are gener 

 ally several feet underground, or else in the heart of otherwise 

 solid trees. 



The queen in those species which normally possess one to each 

 colony, becomes helpless as she increases in size and gravity, for 

 she attains to many times the bulk of the ordinary neuters, which 

 are always un winged. Winged males and females develop from 

 a special brood, and often in such numbers that in spring they 

 swarm until they literally fill the air. They are distinguished 

 from the rest by being more chitinized and darker in color. The 

 great majority of the swarming sexed individuals are doomed to 

 perish, either while on the wing or after falling to the ground, 

 for they are the favorite food of almost all other creatures. But 

 even where not devoured, most of them die without founding new 

 colonies. Swarming is not for the purpose of mating, but it is 

 to be looked upon as an incident in the excessive multiplication 

 of the species, and as a means of inducing cross-fertilization be 

 tween different colonies. 



Upon settling on the ground, the swarming individuals cast 

 off their wings, and if a couple of opposite sex are fortunate 

 enough to enter the outlying burrows of some colony already 

 founded, or to meet a few workers, they are capable of founding 

 a colony themselves. It is only after a female has been duly pro- 



