KITE-FLYING 291 



is probably to reach suitable winter quarters, as their weakness 

 unfits them for the struggle for existence with older and stronger 

 relatives in the original home. And by this instinct they uncon- 

 sciously increase the area of distribution of their species, and 

 contribute to its preservation. On fine autumn days we may see 

 thousands upon thousands of these wind-borne gossamer threads, 

 often compacted into thick web-like masses, some sweeping 

 through the air, some hanging from flowers or other objects, 

 others again spread out over meadows and stubble-fields, where, 

 shining and sparkling in the sun like silver and diamonds, they 

 produce what is known as ' wives' summer ' or ' old wives' 

 summer '. As soon as spiders emerge from their winter quarters 

 in spring-time the same appearance repeats itself, though in 

 much less degree, and is then known as ' maidens' summer '. 

 These shimmering meteors in the air, woven of dew and silver, 

 are described by folk-lore as the cunning handiwork of elves, taught 

 by Freya and Holda, the renowned spinners of Asgaard." 



Two-wiNGED Flies (Diptera) as Kite-Flyers. — One family 

 of this order includes a large number of predaceous forms called 

 by the Germans Dancing- Flies {Empid{s), in reference to the 

 complex aerial evolutions which many of them execute. In some 

 of these (species of Hilard) small silken nets are carried about 

 by the male, attached to his hind-legs, and probably serving as 

 kites which facilitate the movements in the air. Another use 

 of these singular constructions would appear to be the capture 

 and storage of smaller flies to be used as food. It is suggested 

 that the particular purpose served varies with the species. 



