NO. 12 ADAPTATIONS TO SOCIAL LIFE SNYDER 5 



Adaptations to social life among the termites can be seen most 

 clearly by their responses to the three primal urges — hunger, sex. 

 and fear. Unlike man, with a double nervous system, insects have 

 no inhibitions. 



HUNGER 



Lameere has attempted to prove that the neuters of the social 

 insects are of trophogenic origin, i. e., the germinative plasma is 

 labile and is influenced by nourishment. His data on termites are, 

 however, drawn from erroneous sources; the neuters of termites are 

 of blastogenic origin, i. e., there is a distinctive germinative plasma. 

 Although differentiated, nevertheless no caste of any termite is 

 externally clearly differentiated at the time of hatching from the ^gg. 



The male and female parent termites share the " royal cell " in 

 incipient colonies and eat wood as food and care for the young until 

 the latter have developed to the point where they can feed them- 

 selves. In genera where the first brood consists entirely of neuters, 

 they are of smaller size than those in well-established colonies. In 

 genera where no workers exist (in the family Kalotermitidae) the 

 nymphs of the sexual forms perform the duties of the workers. 

 As the colony grows in size the workers or nymphs care for and 

 feed the reproductive forms ; the male lives on and repeatedly fer- 

 tilizes the female. Among the lower termites (Kalotermitidae) the 

 queen remains always active (pi. 2, fig. 5) but queens of the higher 

 termites (Terniitidae) attain a huge size, become inactive and are 

 more dependent, being often imprisoned in the royal cell. They 

 become mere egg-laying machines, and there is a remarkable post- 

 adult growth. The soldier termites have not mandibles adapted for 

 eating wood and have to be fed by the workers or nymphs. The 

 young of termites are also thus fed and cared for in special nur- 

 series. There are two types of special foods — proctodeal (from the 

 anus) and stomodeal (from the mouth). 



In addition to these foods, all termites constantly lick exudate or 

 secretions from the bodies of other termites. In their eagerness for 

 exudate, a portion of antenna, leg or wing pad is sometimes bitten 

 off a member of the colony. Termitophiles or guests are present in 

 termite colonies and these serve as other sources of exudate and 

 special food. Termitophiles occur even in colonies of the lower ter- 

 mites, where they are merely tolerated, but in colonies of the higher, 

 more specialized termites, wonderful physogastric termitophiles occur 

 and are eagerly cared for. Mushrooms are cultivated by species 



