WASPS 197 



If a freshly killed wasp be decapitated and the severed head 

 be turned face downwards, the action of the maxillae will often 

 continue for some time, and may be watched under a hand magnify- 

 ing glass. It will then be seen that the whole of both pairs of 

 maxillae is alternately thrust forward, so that the tongue and 

 apical portions project beyond the teeth of the mandibles, and 

 are then drawn back again, the palps meanwhile being kept 

 in a constant state of flickering motion. The precise action of 

 each individual portion is very difficult to make out, if, indeed, 

 it is known ; but the total effect of the movements is to produce 

 a sucking, pumping action upon objects held between the man- 

 dibular teeth, and to force the extracted juices along a tube 

 whose walls are made up by the several portions of the mouth 

 apparatus. 



Thorax. A short and slender neck unites the head to the 

 thorax. This is composed of three segments, the pro-, meso- 

 and metathorax, and, attached to the last of these, the truly 

 first segment of the abdomen, technically known as the pro- 

 podeum. 1 The first segment of the thorax is black and short, 

 being merely a narrow ring whose sides which are very large 

 and floor are thick and hard ; the roof is detached from the 

 sides, and extends backwards to the insertion of the fore-wings ; 

 it has a yellow stripe on each side. The sides and floor commonly 

 come away with the head when the latter is detached, bearing 

 with them the first pair of legs. The middle segment is much 

 larger, and carries ventrally the second pair of legs, and laterally 

 the first pair of wings. It has two yellow spots, one at the attach- 

 ment of the wing and one just below it on each side ; a portion 

 of it which projects backward dorsally and is separated by a 

 shallow groove bears two further yellow spots. The last seg- 

 ment, which is very short, is firmly united to the preceding, and 

 bears the third pair of legs and the second pair of wings. The 

 propodeum extends from the third segment to the " waist." 

 Both it and the third segment proper may or may not, according 



1 In wasps, ants, bees, and their allies, the " waist " is really between the first and 

 second abdominal segments ; but notwithstanding this, the apparent first (real second) 

 segment of the abdomen is always spoken of as the first, while the true first (now 

 attached to the metathorax) is not counted, but described as the propodeum of the 

 thorax. 



