238 CLAUDE FULLER. 



(2) The smaller castes of a species have fewer joints 

 than the larger. 



(3) The smaller species of termites tend to have fewer 

 joints in the antenna than larger species to which 

 they bear a congeneric relationship. 



15. The variability of the jointing of the antenna is 

 traceable to — 



(1) A newer tendency to be few-jointed as opposed to 

 the primitive condition of being many-jointed. 



(2) The fusing of joint-elements, leading to the ab- 



junction of compound joints. 



(3) Nutrition — e.g. the well-fed individual tends to 



be larger and have more joints in its antenna. 



(4) A probable correlation between the growth of the 



antenna and the development or degeneration of 

 the sexual organs in the infertile castes. 



16. The hereditary and environmental influences affecting 

 joint formation and the general growth of the antenna are 

 so complex, that the number of joints and their relative 

 length and shape have scarcely any taxonomic value without 

 a peculiarly thorough investigation of the species in all its 

 castes and through all the successive phases of its communal 

 development, from the state of being an incipient colony to 

 the state of being a populous and prosperous community 

 throwing off with much regularity' swarms of winged males 

 and females. 



Part I: GENERAL EEYIEW. 

 1. INTRODUCTION. 



As with most insects, so with Termites, the antennas are con- 

 sidered as possessing characters of special taxonomic value. 

 The number of joints composing the organ of this or that caste 

 is invariably cited as important, although for many species a 

 certain amount of diversity is recognised. Unfortunately the 

 tendencv for the number to varv is not alwavs taken into 



