DEVBLOPJIENT OF THE ANTENN.E OF TERMITES. 247 



growth and ecdysis rests mainly upon the development of the 

 spiracles and to but a very limited extent upon antennal 

 conditions. The spiracles of the imago, those of the female 

 in particular, are more specialised than are those of the 

 soldiers and workers ; as such they require an extra moult to 

 come to the stage they are in. When in the fifth instar 

 there is a certain amount of agreement between the spiracles — 

 that is, between those of the imago nymph and of adult 

 soldiers and workers ; and, as these organs do become more 

 specialised with ecdysis, as shown in a previous paper, I see 

 no other explanation. The antennte of the imago termites 

 are on the whole more uniform than are those of the other 

 castes ; if we find the final number of joints is XIX, the 

 nymph of the fifth instar has also XIX. This shows that 

 the organ acquires its full complement of joints in the fourth 

 stadium or with the penultimate ecdysis. Ordinarily the 

 antennae of soldiers and workers acquire their full comple- 

 ment with the third ecdysis or before that, but there are 

 cases which can only be explained on the basis of a certain 

 amount of joint multiplication taking place in the fourth 

 instar. 



Individuals which will become imagos commonly develop 

 wing-sacs in the second instar and these increase noticeably 

 with each ecdysis. 



It has been established by Snyder^ for certain North 

 American termites that, when the transformation from the 

 undifferentiated form to the soldier takes place, the individual 

 becomes quiescent. I have found each ecdysis to be accom- 

 plished during a distinct resting stage, in which the insect 

 assumes a very pupa-like attitude. This has been ascertained 

 for so many species that I feel justified in accepting it as 

 common to all. The period of quiescency is by no means 

 transient and extends over several days. The process of 

 moulting is accompanied by suppressed movements. The 

 exo-skeleton is ruptured dorsally and pushed away by the 

 spines when these are freed from it. It falls aAvay towards 

 ' Suyder, Thomas E., ' Science,' October 3rd, 1913. 



