THE SOLDIERLESS TERMITES OF AFRICA 33 



branches at a higher level. Thus the most significant division of the subfamily 

 separated off the mainly soil- or litter-feeding forms which are characterized by an 

 segment. This also applies to the other 'genus' mentioned by these authors, namely 

 those species of african 'Anoplotermes' known to them. In the latter group the 

 enteric valve was stated to be unarmed. 



One further genus has been described in the subfamily that does not fit the two 

 main groups as defined above. Deligne & Pasteels (1969) give details of the intestine 

 of Labidotermes. There is no mixed segment in this genus and the malpighian 

 tubules are attached to the midgut. The enteric valve armature has only a single 

 large tooth at the anterior end of each cushion. The worker mandibles are similar 

 to those of the Anopiotermes-Speculitermes group. 



indentation of the incisor edge of the left mandible separating the third marginal 

 tooth from the first plus second. Ahmad considered the right mandible to be more 

 specialized in the curved posterior edge of the second marginal, on the grounds 

 that the 'primitive' condition had a straight cutting edge. In this he was influenced 

 by its appearance in most of the otherwise primitive wood-feeding groups of termites. 

 It should be noted, however, that in the primitive cockroaches, Pohphaga and 

 Cryptocercus, as well as most of the rest of this group, the right second marginal has 

 a convex anterior and concave posterior margin. In first instars of Archotermopsis 

 the same applies, the tooth becoming straighter in adults. It seems probable that 

 this straightening of the right second marginal tooth is an adaptation to feeding 

 on fibrous materials that require shearing. This is supported by the same tooth in 

 the soldier caste of some wood-feeding primitive forms. When the expression 

 of the gene complex controlling mandible development switches to the piercing 

 soldier function, the tooth reverts to the cockroach form. Thus it would seem 

 that where such a tooth occurs in otherwise primitive species it is itself a retention 

 of an unspecialized condition. 



When Noirot & Noirot-Timothee (1969) came to consider the intestinal structure 

 of the Amitermitinae they found two basic patterns. One is found in the group of 

 genera including Anoplotermes, Speculitermes and Eitrytcrmes. The gizzard lacks 

 armature, the mesenteron overlaps with the proctodeum to form a mixed segment, 

 and the malpighian tubules are attached separately within the epithelium of the 

 mesenteron. The enteric valve is unarmed. The other type occurs in the rest of 

 the subfamily with one or two exceptions. The mixed segment is always well 

 developed, often with the termination of the mesenteron to some extent inflated. 

 The first segment of the proctodeum is commonl)' dilated and the malpighian 

 tubules are inserted, usually in pairs, on the mesenteric-proctodeal junction. The 

 gizzard carries typical armature. Associated with this group also are the genera 

 Protohamitermes, Prohamitermes, Globiternies and Synhamitermes, which differ 

 only in that the malpighian tubules are carried on evaginations at the junction of 

 mesenteron and proctodeum rather than directly attached. Thus apart from Pro- 

 tohamitermes these authors agree with the basic division postulated by Ahmad. 

 The mandibles of the latter genus are primitive in form and show some general 

 resemblance of shape to the other main branch. Its gut is one of the more special- 

 ized, and clearly indicates that its affinities are with the Amitermes branch although 



