SOCIAL LIFE 253 



describes them as a ** perplexing assemblage of assassins, 

 scavengers, satellites, guests, commensals, and parasites." 



Wasps, bees, and ants, among which are included the 

 vast majority of social insects, belong to the Hymenoptera, 

 one of the most highly specialised of all the orders of the 

 insect class. It is, however, of great interest to find that 

 an elaborate social life, depending on the growth of an 

 enormous family, is characteristic of a lowly organised 

 group — the Termites, which though often called *' white 

 ants," have no near relationship to true ants, but belong to 

 a comparatively primitive order, the Isoptera. Among the 

 Embiidae, a tropical and sub-tropical family closely akin to 

 the termites, there is to be noticed an incipiently social 

 habit analogous to that characterising some of the '* solitary " 

 wasps and bees. Many male embiids are winged ; the 

 wingless females tend their eggs and young much as the 

 mother-earwig (p. 210) cares for her brood. A. D. Imms 

 (191 3) describes how in the Himalayan Embia major, " when 

 the young larvae are hatched, they remain around the parent 

 female, who conceals them, so far as she is able by means 

 of her body." These insects spin, from glands situated 

 in the fore-feet, an abundance of silken thread, and thus 

 construct extensive webs and galleries in which their 

 families carry on a primitive community life. All the 

 adults among the Embiidae are normal fertile males or 

 females ; there is no worker caste. 



In a termite society, on the other hand, the immense 

 majority of members are infertile, wingless *' workers " 

 (Fig. 64, d) with small heads and jaws, together with a 

 smaller though considerable number of larger-headed, 

 long-jawed '* soldiers " (Fig. 64, c). While in the bee or ant 

 community all the infertile insects are females, the worker 

 and soldier castes among the termites may belong to either 

 sex. The differences between the various members of a 

 termite society were formerly believed to be induced by 

 differences in feeding, but the researches of E. Bugnion 

 (1913) and Caroline B. Thompson (1916) have demon- 

 strated that, at least in some cases, the caste characters of 



