SCIENTIFIC NOTES. 55 



about some of the markings further on. The marked peculiarities of 

 the perfect insects are the long slender abdomina, the long pointed 

 wings not overlapping at the base, and the extremely short antennae. 

 But the first thing to attract notice in this group is the vibratory, pen- 

 dulum-like flight of the male Imniidi, which may be seen in the early 

 twilight of a summer evening, swinging leisurely backwards and forwards, 

 as if it had nothing else to do. It seems always to have been accepted 

 that this oscillating flight had something to do with the opposite sex, 

 and a theory was long held that there was a female concealed in the 

 herbage below, and that his motions were made in the desire to attract 

 her notice, much, I suppose, as the males of certain birds and other 

 animals strut and posture to gain the favours of their lady love. Many 

 a fruitless search have I made to discover the hidden female. The 

 slight changes of position he sometimes makes, were assumed to be the 

 result of her motions below, and I have over and over again tried to 

 follow these changes, thinking I should thus be guided to her. The 

 male is generally so intent upon what he is doing, that you may stand 

 close to him. But my search was always in vain, the solution escaped 

 me for many years, and even when Dr. Chapman solved the problem, 

 and recorded as long ago as 1876 {E.AI.M., vol. xiii., p. 63) the 

 meaning of this exposed hovering, I, unfortunately, overlooked the 

 record. Accident at length revealed the secret. I was passing through 

 an uncultivated field where humidi was unusually abundant. Stopping 

 for a moment to watch them, I saw a female fly to one of the oscillating 

 males, which immediately followed her down. For a moment I did not 

 comprehend what I had seen, but another female rose, and I noticed 

 this time that one came in actual contact with the male, which also flew 

 down after her, and, when I found them on the herbage, they were 

 already paired. Before I left the field I had seen this repeated again 

 and again, and had not the slightest doubt of the meaning of the 

 peculiar motions of the male. This, subsequent observations have fully 

 confirmed. The male humuli flies in this conspicuous manner that the 

 female may see him, and his light colour very greatly assists this. Dr. 

 Chapman, in recording what he had seen, expressed the opinion that 

 it must have been noticed before, and, really, when you have once seen 

 it, you cannot help thinking as he did, that it must have been observed 

 long ago. The flight of the female at this time is, as he pointed out, 

 very different from her flight when she is dropping her eggs over the 

 herbage, and which, so far as I have seen, is always done later in the 

 evening. There is another matter connected with the flight of humuli 

 that has not, I believe, been recorded. That is, the fact that when 

 several males are flying in close proximity, they amuse themselves by 

 bumping together much as flies do around our curtain fringes. I had 

 noticed this once or twice previously, but merely thought they were 

 flying rather close together, and accidentally came in contact ; but last 

 summer I convinced myself that it was no accident, but that they were 

 really at play, I was on the railway side endeavouring to take Acidalia 

 subsericeata, when I noticed two male humuli flying together. I stood 

 and watched them for some time, noticing that they occasionally came 

 in actual contact, but not attaching any meaning to the act ; presently, 

 a third male appeared a few feet away. It quickly drew near the other 

 two and then joined them, all flying close together, and two, or some. 



