SOUTH AFRIOAN TERMITES. 49 



medial root, and cubital root. The anterior is called 

 the radial because the scape continues uninterruptedly into 

 the wing-sac and precedes the rib to which the name radius 

 has been applied (see Section III). In Calotermes and 

 Cryptotermes the post-costal and sub-costal are regu- 

 larly attached to the radial trachea, the one to the root, the 

 other to the scape. In those species presenting no post-costal 

 the sub-costal is regularly attached to the radial scape. The 

 middle root is called the medial because it is that of the 

 trachea which precedes the media. The posterior is described 

 as the cubital because the scape enters the wing-sac unin- 

 terruptedly and precedes the cubitus ; to its base is attached 

 any rudimentary anal that may be present. In H. viator 

 there are usually two and occasionally three, in Termes 

 natalensis there are occasionally two, more often three, 

 basal connections. When there are two they are the radial 

 and the cubital, and the radial trachea then carries the post- 

 costal and sub-costal, as in the other species, whilst the cubital 

 trachea is in a duplicated condition, the inner stem preceding 

 a typical cubitus, the outer a pseudo-media. When there 

 are three connections, the condition is due to the occasional 

 independence of the post-costal trachea, fig. 78 (PI. VII), an 

 independence which manifests itself quite erratically in T, 

 natalensis as regards any of the four wings of a given 

 insect. At the base of the cubital trachea of T. natalensis 

 there is an anal trachea ; this does not grow into the wing-sac, 

 however, but turns inwards and enters the thoracic cavity, 

 figs. 182, 186 and 187 (PI. XI). 



In Microtermes there are usually two basal connections 

 and occasionally three. When two are present they are as in 

 T, natalensis, the cubital being always duplicated (the 

 post-costal appears to be often wanting, but when present is 

 attached to the radial). When three are present the extra 

 one is the medial ; thus a wing-sac of the species of this genus 

 may present an independent medial in company witli a 

 pseudo-medial and a cubital, fig. 200 (PI. XI). 



In Rhinotermes putorius there are three roots; these I 

 VOL. 4, PART 1. 4 



