INSECTS: THEIR EARS AND EYES. 165 



male. This sex has an extraordinary power of discover- 

 ing the female at immense distances, even though she be 

 perfectly concealed ; and will crowd towards her from all 

 quarters, entering into houses, beating at windows, and 

 even descending chimneys, to come at the dear object of 

 their solicitude. Collectors call this mode of procuring 

 the male " sembling," that is, " assembling" because the 

 insects of this sex assemble at one point. It cannot be 

 practised with all insects, nor even with all moths ; with 

 this family, Bombycida, it is in general successful ; and of 

 these, none is more celebrated for the habit than the Oak 

 Egger. The very individual whose antenna has furnished 

 us with this observation was taken in this way ; for having 

 bred a female of this species the evening before last, I put 

 her into a basket in my parlour. One male, the same 

 evening, came dashing into the kitchen ; but yesterday, 

 soon after noon, in the hot sunshine of August, no fewer 

 than four more males came rapidly in succession to the 

 parlour window, which was a little open, and, after beating 

 about the panes a few minutes, found their way in, and 

 made straightway for the basket, totally regardless of their 

 own liberty. 



It must be manifest to you that some extraordinary 

 sense is bestowed on these moths, or else some ordinary 

 and well-known sense in extraordinary development. It 

 may be smell ; it may be hearing ; but neither odour nor 

 sound, perceptible by our dull faculties, is given forth by 

 the females ; the emanation is far too subtle to produce 

 any vibrations on our sensorium, and yet sufficiently 

 potent, and widely diffused, to call these males from their 

 distant retreats in the hedges and woods. I think it 

 highly probable that the great increase of surface given to 

 the antennae by the plumose ramification we have been 

 observing, is connected with the faculty; perhaps every 

 bristle of the spiral whorls is a perceptive organ, con- 

 structed to vibrate with the tender undulations that circle 



