SOUTH AFRICAN TERMITES. 7o 



radial found. This is illustrated by figs. 103a and b. Tlie 

 chief interest attaching" to this example lies in its uniqueness. 

 Figs. 104 to 134 (Plates VIII-IX) illustrate a number of 

 wings selected from insects of one nest series which show a 

 wide range of diversities and abnormalities. For convenience 

 the word " wing " will be used instead of " figure," and it 

 will be understood that whilst the drawings essay to pictui-e 

 the actual arrangement as far as possible, they do not show 

 the marked difference that actually exists between the rigid 

 and the flexible ribs. 



Wings 104, 105, 108, 109, 1J2, 1 14 ai-e all normal. Wings 

 107, 110, 111 are normal, but illustrate the occasional and 

 more or less simple furcation of the media. 



Wing 106, otherwise normal, possesses a renuii-kably well- 

 branched media. 



Wing 115 illustrates a unique case in which the media is 

 drawn close to the radius. 



Wing 116, whilst apparently but a more exaggerated 

 illustration of an amply branched media, as in wing 1()(), 

 more probably owes its condition to a duplicated medial. 



The condition of wing 117 can be safely traced to a dupli- 

 cated medial trachea. This wing is remarkable for the sharp 

 and deep incurving of the tips of both media, the pre- 

 existing trachea3 in this case, probably turning back as 

 decidedly as trachetc do in the wing-sacs of Cry ptotermes, 

 a feature that is further illustrated by wing 126. 



Wing 121 is a hind wing in which the media is attached to 

 the cubitus instead of to the radius, and this unusual state of 

 affairs is accompanied by a short extra rib which occupies 

 the place where the media would normally stand. Such a 

 rib may arise from any one of several tracheal conditions. 

 It might be due (a) to an extra but atrophied medial; (b) to 

 a branch of the radial, as in fig. 103a (PI. VII) ; (c) to a 

 duplication of either the post-costal or the sub-costal, as \u 

 figs. 100 and 102a. 



Wing 122 : this abnormality can readily be traced to a 

 duplicated medial, as in fig. 98a, the two tracheas becoming 



