OBSERVATIONS ON GIGANTIOPS DESTRUCTOR. 197 



Lewis ('82), Wroughton ('92), and Bingham ('03). Lefevre 

 states that it can make leaps of 20 to 25 cm., and Lewis saw it rise 

 into the air to a height of 5 or 6 inches till exhausted, when its 

 leap did not exceed an inch. Wroughton says : " The single speci- 

 men of the genus, which I have had the luck to find, made leaps 

 of a foot or 1 8 inches with perfect ease, exactly like a grasshopper. 

 I had much trouble in securing this specimen, and, when I suc- 

 ceeded, I found she could sting better than she could leap." Un- 

 fortunately we have no observations on the modus saltandi of this 

 curious insect. Its hind legs are really very short and even thinner 

 than those of many nonsalient ants as indicated in the figure of the 

 hind femur of a worker H. saltator Jerdon (Fig. 2c). As this 

 ant is nearly of the same size as the specimens selected for the 

 other femora (a-d*), and as the outline is drawn to the same scale, 

 it will be evident that no such feats of leaping as described by 

 Wroughton can be performed with such appendages. We must 

 conclude, therefore, that the mandibles are employed for this pur- 

 pose, but how they function is a matter of pure conjecture till the 

 living insect can be carefully studied. It is conceivable that when 







about to leap the Harpegnathos opens her mandibles slightly till 

 the two basal teeth just barely touch, and that she presses the tips 

 of the mandibles against the ground so that their long, slender, and 

 probably very elastic blades are more arcuately bent. \Ve may 

 suppose, moreover, that if the two teeth are suddenly permitted to 

 slide over each other, with a concomitant sudden unbending of the 

 mandibles, the insect would be precipitated forward much like a 

 very elastic strip of metal or whalebone bent in an arc and sud- 

 denly released. It is less probable that the insect leaps by insert- 

 ing the tips of the mandibles in the ground and bending them in 

 the opposite direction, i.e.,, by more nearly straightening them and 

 then suddenly allowing them to return to their original curvature. 1 



i Since this paragraph was written I find that Professor Forel (1921, p. 

 47) gives some notes on the method of leaping employed by Harpegnathos. 

 He states, apparently on the authority of some correspondent in India or 

 China, that this ant " fait des bonds formidables de plus d'un metre a 1'aide 

 de ses longues mandibules un peu recourbees en haut. La tete entiere se 

 recourbe sous le corps, se rejettant ensuite en avant, un peu a la maniere du 

 thorax de nos insectes d'Europe nommes taupins." 



