230 NATURAL HISTORY. [CH. XV. 



choral dancers alternately rising and falling in the 

 full sunbeam, and appearing so transparent and 

 glorious that they scarcely resembled any thing ma- 

 terial — they reminded the observers of angels and 

 glorified spirits, drinking life and joy in the efful- 

 gence of the divine favour. 



" Thick in yon stream of light, a thousand ways 

 Upward and downward thwarting, and convolved, 

 The quivering nations sport ; till, tempest-wing'd, 

 Fierce winter sweeps them from the face of day. 

 Even so luxurious men unheeding pass 

 An idle summer's life in fortune's shine— 

 A season's glitter ! Thus they flutter on, 

 From toy to toy, from vanity to vice, 

 Till, blown away by death, oblivion comes 

 Behind, and strikes them from the book of time." 



Thomson's Seasons. 



No one will deny the beauty of these fine lines, 

 and w^e are persuaded that their force will not be 

 considered in the least diminished, although some 

 of the tribes of these " quivering nations" are able 

 to bear the sweeping storms of winter. 

 ; The winter midges Trichocera {hyemalis) afford 

 another instance of the numerical excess of certain 

 species, and also of that spirit of sociahty which is 

 not uncommonly observed in insects. These deli- 

 cate little creatures may often be seen, throughout 

 the winter and early spring months, assembled in 

 troops, alternately rising and falling with rapid 

 revolutions, in some sunny nook, even though the 

 ground may at the time be covered with snow. It 

 is a pleasant sight to watch their motions at a time 

 when all the rest of nature seems to be suffering 

 beneath the iron blast of " fierce winter's breath in- 

 tensely keen." The opinion, that in these assem- 

 blages midges and other insects are under the in- 

 fluence of a principle of sociality, has been con- 

 sidered by a recent author to be more poetical than 

 correct ; their congregating together being supposed 

 to arise neither from gregarious feelings nor for 

 mutual assistance, but merely because they are 



