INSECTS. 147 



to the greater or less density of the mass, from that of light 

 vapour to black smoke, the columns not only differing in this 

 respect from each other, but each column being frequently 

 different in different parts. They might have been mistaken 

 for dark smoke-wreaths but for their general uniformity of 

 breadth, and for a graceful and easy undulation, similar to that 

 of the tail of a boy's kite, when at some height and tolerably 

 steady. The individual insects flew about in each column in 

 a confused and whirling multitude, without presenting in their 

 mazy dance any of those regular figures which Gnats frequently 

 exhibit over pools of water, while the motion of their wings 

 filled the air with a peculiar and not unmelodious humming 

 noise. The columns rose perpendicularly to the height of from 

 30 to 60 feet, and in some instances to the height of 80 feet. 

 They were equally abundant over trees of every kind, as ash, 

 beech, birch, poplar, &c. ; and so numerous were these distinct 

 columns, that so many as from 200 to 300 were visible at 

 the same time. As each column was every instant undergoing 

 a change in density of colour, diameter, elevation, or form, 

 the phenomenon was one of exceeding interest, especially 

 as connected with the living myriads which, in these aerial 

 gambols, gave expression to their enjoyment." 



If we ask, why do they thus associate together? by what 

 principle are they impelled to congregate in this ever-varying 

 dance ? we arc unable to give any reply to the question more 

 just, or more philosophical, than that suggested by the Poet: 



" NOT wanting here, to entertain the thought, 

 Creatures that in communities exist, 

 Less as might seem for general guardianship, 

 Or through dependence upon mutual aid, 

 Than by participation of delight 

 And a strict fellowship of lov r c combined ; 

 What other spirit can it be that prompts 

 The gilded Summer-flies to mix and weave 

 Their sports together in the solar beam, 

 Or in the gloom of twilight hum their joy?" Wor.t^oinn. 



