230 [October, 



(the details of this strugi^le I could not make out), and that she 

 enjoyed it while copulation was in progress. 



It was soon quite evident that this was the normal course of 

 events. In all, six " visitors" were caught just before copulation would 

 apparently have taken place ; all were males and all bore living prey in 

 notably good condition (A seventh, also a male with live prey, was 

 caught on June 14th). In the case of four pairs, caught as soon as 

 possible (five seconds or less) after coupling, the prey was a little 

 rumpled and was in the possession of the female, while with seven 

 other pairs caught at varying intervals (up to nearly ten minutes) 

 after coupling the condition of the prey naturally got progressively 

 worse the longer the female had enjoyed it, its last state being 

 a crumjded ball of shrivelled remains. Altogether fourteen females 

 were seen at this spot, and in eleven cases copulation was observed to 

 take place as described, while three females failed to obtain partners 

 and finally gave up the dance altogether at about 5.30 p.m. In no 

 case was a female ever in possession of prey until supplieil with it by 

 her swain, nor did two or three Perlids, which came within very easy 

 range, appear to have any particular interest for the dancers, who 

 made no effort to seize them. 



On .Tune 1-ith, during a dull and gusty interval, I saw a male 

 lying close among some grass, and on inspection found that he was 

 clasping a Perlid. After about twenty minutes the wind dropped 

 and the sky cleared a little, and the self-denying male, who had 

 refrained from gratifying his appetite all this time, at once made for 

 the fir trees (about thirty yards away), still carrying his burden. 

 I was able to keep within a short distance of him, and had the 

 satisfaction of seeing him pair WMth one of two females who were 

 dancing at the time. I caught the pair a few seconds after coupling, 

 and found the Perlid in possession of the female. 



On June 15th 1 took a male sitting among grass holding an 

 undamaged Bibionid {Blbio varipes). 



During copulation, after a short flight (generally of not more 

 than twenty yards), the male usually hung by the front pair of legs 

 to a twig or blade of grass, sup|)orting thus the whole weight of 

 himself and partner ; the middle legs clasped the thorax of the 

 female, while the hind pair of tarsi supported the prey in position 

 beneath her proboscis, the apical part of the femora meanwhile 

 firmly compressing her upturned abdomen. 



The hind legs of the female hung idle, while with the two front 

 pairs she manipulated the prey, kneading it as one who sucks an 



