24 B. GEASSI AND A. SANDIAS. 



It is only with much patience that such phenomena can be 

 determined, but it can be done with complete certainty. It 

 has been especially noticed that an incipient royal substitute 

 was approached after a recent ecdysis by different individuals 

 which administered saliva to it ; and it should be added that 

 after the last moult the nymphs make repeated acts of deglu- 

 tition to swallow the saliva secreted by their own glands. 



Moreover saliva is seen to trickle from the labium of, and 

 to be swallowed by incipient royal substitutes which have just 

 finished moulting, if they are not supplied with it by their 

 companions. The secretion may stop for a few minutes and 

 then recommence. The forms which secrete saliva for others 

 are large larvae or nymphs.* 



Individuals fed with saliva exhibit a great transparency of 

 the abdomen, an indication that they are in progress of becom- 

 ing royal substitutes. They contain no Protozoa, or contain 

 them dead, and their death or disappearance is most probably 

 a direct result of the action of the saliva. 



It is a moot point whether the maturation of the generative 

 organs is due solely to the saliva or to the absence of Pro- 

 tozoa as well ; but the latter, as my previous remarks show, is 

 not by itself a sufficient cause. 



I have frequently asked myself whether the Protozoa have 

 not an important digestive function, since the comminuted 

 wood passes almost entirely through their bodies. It is pro- 

 bable, but not proved. 



^Termitidse can go without food for several days ; the 

 soldiers especially eat much less than other forms, and can 

 endure more than eight days' abstinence. Exercise, therefore, 

 costs the colony little. 



As is only natural, when the fseces have repeatedly passed 

 and repassed through the bodies of the insects, they are no 

 longer sufficient to support life. For this reason a nest of 

 nothing but soldiers dies, because they are incapable of gnaw- 

 ing up fresh wood. But the addition of a single large larva 

 to a colony of ten or a dozen soldiers is enough to keep them 

 alive.* 



