SPIDERS' NESTS. 57 



nipples supplied one thousand separate fibres, in 

 which case the slender filament of the spider's 

 nest must be made up of five thousand fibres. By 

 applying the whole, or a part, of this apparatus 

 to her work, the spider can make the thread stout 

 or fine at pleasure : thus the webs for entrapping 

 flies are very slight and fragile ; but the nest for 

 securing the eggs is much stronger, to afford them 

 shelter from the cold. The threads are wound 

 loosely round the eggs in a shape similar to that 

 of the silkworm's cocoon. The colour of the silk 

 is generally grey, becoming blackish on exposure 

 to the air : sometimes it is pale yellow, and also 

 of very fine quality ; but this is the production of 

 comparatively rare species, which could not be 

 depended on for the purposes of manufacture. A 

 spider's nest preserved by the writer during the 

 last winter was of a beautiful yellow, almost 

 approaching that of the cocoon of the silkworm. 

 As spring approached it increased in bulk and 

 became rather paler, until at last a dark appearance 

 in the centre betokened the bursting of the eggs. 



