SPIDERS' EGGS AND THEIR ENVELOPES. 135 



than her body, with which, on alarm, she makes off with all 

 possible expedition. These balls, popularly known as Spiders' 

 eggs, are in fact made up of a numerous group of them, 

 enclosed within a woven envelope ; and the way in which these 

 spinning mothers proceed to 



" tie " their " treasure up in silken bags," 



is another very curious exercise of their weaving art. Using 

 her own body (after the manner of a nest-building bird) as a 

 measure for its circumference, the spider spins, first, the 

 lower half of her intended covering, which in this stage of its 

 progress resembles a cup or nest. She then proceeds to lay 

 her eggs, and over these, when piled up within, weaves a 

 convex cover which, united with the receptacle at bottom, 

 renders the ball complete. These silken egg-purses vary in 

 colour ; those of the House-Spiders being white, of the common 

 Garden yellow, of other out-door species blue or greenish. 



In form they are usually globular, but variations from this 

 shape are occasionally met with. Last summer we noticed an 

 exceedingly pretty one in the instance of a small greenish Spider, 

 variegated with white, of which we found many on the leaves 

 of a wall plum tree, keeping watch and ward over their nests. 

 These, which were attached to the under side of the leaf, were 

 white, and of an elegant urn-like shape, something resembling 

 the seed case of a poppy. Bound the circumference of the top 

 or cover, were five, and in other specimens, seven points, 

 another rising pyramidically from its centre. 



