XVI TERMITIDAE 36 1 



immediately under the supra-oesophageal ; there are three thoracic 

 and six abdominal ganglia. The nervous system apparently 

 differs but little in the various forms, or in the different stages 

 of life, except that in the fertile females the abdominal ganglia 

 become so much enlarged that they even exceed the brain in size. 



The testes are unusually simple ; each consists of eight capsules 

 opening into the vas deferens ; the two vasa converge and are 

 continued as a short ejaculatory duct ; at the point of convergence 

 there is a pair of curled vesiculae seminales. 



The ovarian system is also simple ; there is a variable number 

 of elongate egg-tubes, each of which opens separately into the 

 oviduct ; the two ducts unite to form a short uterus, on which 

 there is placed first a spermatheca, and near the extremity a 

 convolute tubular sebific gland. The number of egg- tubes is 

 subject to extraordinary variation, according to the species, and 

 according to the age of the fertilised individual. 



Social Life. Termites live in communities that consist 

 sometimes of enormous numbers of individuals. The adult forms 

 found in a community are (1) workers; (2) soldiers; (3) winged 

 males and females; (4) some of these winged forms that have 

 lost their wings. Some species have no worker caste. The 

 ijidividuals of the third category are only present for a 

 few days and then leave the nest in swarms. In addition 

 to the adult individuals there are also present various 

 forms of young. The individuals that have lost their wings 

 are usually limited to a single pair, king and queen ; 

 there may be more than one king and queen, but this is not 

 usual. The king and queen may be recognised by the stumps 

 of their cast wings, which exist in the form of small triangular 

 pieces folded on the back of the thorax (Fig. 235). The con- 

 tinuance of the community is effected entirely by the royal pair ; 

 they are the centres of activity of the community, which is thrown 

 into disorder when anything happens to them. Usually the pair 

 are physically incapable of leaving the nest, especially the queen, 

 and frequently they are enclosed in a cell w^hich they cannot leave. 

 In consequence of the disorganisation that arises in the com- 

 munity in the absence of a royal pair, Termites keep certain 

 individuals in such a state of advancement that they can rapidly 

 be developed into royalties should occasion require it. These 

 reserve individuals are called complementary by Grassi ; when 



