Chap. X.] HYMENOPTERA. 353 



the females are always orange or yellow, so that, supposing 

 Agrion to be descended from some primordial form hav- 

 ing the characteristic sexual colors of the typical Libelluloe, 

 it would not be surprising that a tendency to vary in this 

 manner should occur in the females alone. 



Although many dragon-flies are such large, powerful, 

 and fierce insects, the males have not been observed by 

 Mr. MacLachlan to fight together, except, as he believes, 

 in the case of some of the smaller species of Agrion. In 

 another very distinct group in this Order, namely, in the 

 Termites or white ants, both sexes at the time of swarm- 

 ing may be seen running about, " the male after the fe- 

 male, sometimes two chasing one female, and contending 

 with great eagerness who shall win the prize." ^^ 



Order, Ilyinenoptera. — That inimitable observer M. 

 Fabre," in describing the habits of Cerceris, a wasp-like 

 insect, remarks that " fights frequently ensue between the 

 males for the possession of some particular female, who 

 sits an apparently unconcerned beholder of the struggle 

 for supremacy, and, when the victory is decided, quietly 

 flies away in company with the conqueroi"." Westwood " 

 says that the males of one of the saw-flies (Tenthredinte) 

 "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 recognizing 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 



'* Kirby and Spence, 'Introduct. to Entomology,' vol. ii. 1818, p. 35. 

 *^ See an interesting article, " The Writings of Fabre," in ' Nat. Hist, 

 Review,' April, 1862, p. 122. 



" 'Journal of Proc. of Entomolog. Soc.' Sept. Y, 1863, p. 169. 

 16 



