330 THE DESCENT OF MAN. 



are orange or yellow; so that supposing Agrion to be 

 descended from some primordial form which resembled the 

 typical Libullulae in its sexual characters, it would not be 

 surprising that a tendency to vary in this manner should 

 occur in the females alone. 



Although many dragon-flies are large, powerful and fierce 

 insects, the males have not been observed by Mr. Mac- 

 Lachlan to fight together, excepting, as he believes, in some 

 of the smaller species of Agrion. In another group in this 

 order, namely, the Termites or white ants, both sexes at 

 the time of swarming may be seen running about, '*the 

 male after the female, sometimes two chasing one female, 

 and contending with great eagerness who shall win the 

 prize."* The Atropos pulsatorius is said to make a noise 

 with its jaws, which is answered by other individuals, f 



Hymenoptera. That inimitable observer, M. Fabre, { in 

 describing the habits of Cerceris, a wasp-like insect, 

 remarks that e< fights frequently ensue between the males 

 for the possession of some particular female, who sits an 

 apparently unconcerned beholder of the struggle for suprem- 

 acy, and when the victory is decided, quietly flies away in 

 company with the conqueror/' Westwood says that the 

 males of one of the saw-flies (Tenthredinas) "have been 

 found fighting together with their mandibles locked." As 

 M. Fabre speaks of the males of Cerceris striving to obtain 

 a particular female, it may be well to bear in mind that 

 insects belonging to this order have the power of recogniz- 

 ing each other after long intervals of time, and are deeply 

 attached. For instance, Pierre Huber, whose accuracy no one 

 doubts, separated some ants, and when, after an interval of 

 four months, they met others which had formerly belonged 

 to the same community, they recognized and caressed one 

 another with their antennae. Had they been strangers they 

 would have fought together. Again, when two commu- 

 nities engage in a battle the ants on the same side some- 



* Kirby and Spence, " Introduct. to Entomology," vol. ii, 1818, 

 p,85, 



f Houzeau, " Les Facultes Mentales," etc., torn, i, p. 104. 



i See an interesting article, "The Writings of Fabre," in "Nat 

 Hist. Review," April, 1862, p. 122. 



"Journal of Proc. of Entoinolog, Soc,," Sept. 7, 1863, p. 169. 



