FORMICA. 255 



females, a very large number of dealated females, a few males, and 

 pseudogynes in very considerable numbers. 



Such a populous colony, apparently in a most prosperous con- 

 dition, with plenty of both dealated females and ordinary workers, 

 appears to entirely controvert the theory that pseudogynes have 

 been brought about by the workers endeavouring to change female 

 larvae into workers or vice versa to replace the scarcity of the 

 latter caused by the presence of a beetle of the genus Atemeles. 

 It may be added that pseudogynes occur in nearly every nest over 

 the whole large area inhabited by F. rufa at Nethy Bridge, and that 

 the most diligent search has never been rewarded by the discovery 

 of an Atemeles, or its larva, there. 



Of all the indigenous ants, as pointed out by Latreille in 1802, the 

 winged forms of this species appear first ; he says the winged females 

 are to be found towards the middle of spring, either on the nests 

 or at some distance from them, or even in the interior of towns, 

 running on the walls and often without wings 4 . 



The winged sexes occur from April to August. Schenck records 

 a winged female two hundred paces from a nest at Wiesbaden on 

 April 26th 26 ; the earliest date given by Forel for isolated winged 

 females in Switzerland is May 10th 38 ; Collett recorded that in 

 1883 the males began to appear at Guestling on May 21st and the 

 females a week later 46 ; and Bignell found winged females on a 

 nest at Shaughbridge on April 22nd, 1897 57 . 



On April 17th, 1912, I found rufa males out on fir posts, some 

 distance from any nest, at Wellington College 89 , which is the earliest 

 date of which I am aware for either of the winged sexes of this 

 species. Plant states that swarming takes place from the end of 

 July to the beginning of September 17 , but he does not say that he 

 has actually seen a marriage flight, nor am I aware of any record 

 of the actual mating of the sexes, other than the one to be men- 

 tioned shortly. Forel says he has seen the males and winged 

 females of rufa ready to fly in the Engadine on July 10th, 1871 38 , 

 but he writes of the genus Formica " One never sees the swarms 

 formed by the $ and the <J of this genus ; at least I do not know 

 of any description, and I have never seen it. The coupling cer- 

 tainly does not take place in the air, but may probably be on the 

 tops of trees or hills." Standen records seeing a number of speci- 

 mens of F. rufa flying at Grange on August 15th, 1909, at four 

 o'clock in the afternoon, the day being dead calm and very hot ; 

 a great many gulls were seen to be catching the ants in the air 76 . 



On June 15th, 1911, I actually witnessed the coupling of the 

 sexes at Aviemore in the middle of the afternoon. A number of 

 rufa males and females were seen flying about in a timber yard, 

 running about on a large mound of sawdust in the hot sunshine, 

 flying off and settling on it, the males appearing to rise more 

 easily than the females. Copulation took place on the mound ; 



