670 TERMITES OR WHITE ANTS. 



CHARACTERS. 



The enormous number of individuals in a nest, all of whom may be 

 considered as the children of the same parents, provides material for 

 the study of normal variation and of specitic limits scarcely to be met 

 with elsewhere. The great difference of charactei" in the different 

 castes also introduces new conditions in the classitication of species, 

 and in the stud}^ of heredity, not often to be met with. 



In the genus Termes the soldier is ))y far the best caste to determine 

 species from; not only is the soldier easier to determine than the 

 male, but it is found in almost every nest, and usually wherever the 

 workers go. Though the imago was the caste on which Hagen founded 

 most of his species, though it is the form found fossil in amber, 

 though it is the form caught flying round a lamp at night, yet it is 

 generally absent from the nests, and is often insufficient for the deter- 

 mination of species. I have not found the characters of the wings 

 ver}^ useful or reliable. In one case I have based species on differ- 

 ences in the imago, though I could see no difference whatever in the 

 soldier; but as a rule my species are based chief}- on apparent differ- 

 ences in the soldiers. 



There are two external characters, which are correlated in the 

 soldiers and the males of the genus Teniics. The abdominal papilUe 

 show a corresponding degree of development, and the number of 

 segments of the antennie is approximately in the proportion of 8 to 9. 

 The characters of the antennae are probabl v more important than any 

 others in the determination of the species. It is easy enough with a 

 little care to determine whether the apical segments are present or, as 

 often happens, are broken off, for the apical segment is of a different 

 shape from the others. Although the segments of the antennas are 

 fewer in soldier than in the male, they are generally longer and more 

 cylindrical, so that the antennae of the soldiers are often as long as or 

 longer than those of the imago. The antennas of the workers, on the 

 other hand, are always much shorter, yet the number of segments 

 which compose them is never less than in the soldier and never more 

 than in the male. The actual length of the antenna? in the genus 

 Termes seems to be but little correlated with the actual number of 

 segments which compose them, whether we compare the different 

 species, or whether we compare the different castes. Long antenn.e 

 go with long legs, and this is true whether we compare caste or spe- 

 cies. Long legs and long antennte go with nuich walking and forag- 

 ing; and this is true when we look to differences Ijetween species, but 

 not when we look to differences between castes. Soldiers with long, 

 slender legs belong to species which forage for food at a distance from 

 the nest; soldiers with short, stout legs belong to species sluggish in 

 their movements, and which venture but little from home. 



