194 INTRODUCTION TO ZOOLOGY CHAP. 



of the water, bringing it down to eat in peace in her little 

 air-bell below. Late in the summer, she lays her eggs, 

 separating off by a transverse wall of silk the upper part of 

 the dome, to act as a "nursery." In a nest, very similar, but 

 at a greater depth in the water and made of denser silk, she 

 spends the winter in a more or less torpid condition. 



It is said that the young, when they become independent, 

 do not at first weave nests for themselves, but fill the 

 empty shells of small water snails with air and then float with 

 them to the surface. The male spider also constructs an air- 

 bell, at any rate in the mating season, when it is to be found 

 close by that of the lady spider. In the water spider, alone 

 amongst spiders, the male is larger than the female. 



The body of a water spider is covered with short hairs, 



making the surface like velvet; consequently air becomes 



entangled amongst the hairs, so that though the body looks 



black out of water, under water it looks as if surrounded 



by a globule of quicksilver and is a really beautiful object. 



Running Some spiders, though living on the ground, 



Spiders or spin no web at all, but depend entirely on their 



Wolf Spiders hunting powers for obtaining sufficient food. The 



L ae '' brownish-coloured Lycosidae are amongst these. 



Many of them hide themselves, when not hunting, in a little 



FIG. 127. Head of the Wolf Spider 

 FIG. 126. The Wolf Spider (Lycosa seen from the front. 



picta) carrying her egg-bag, e. p, Pedipalp ; m, jaw. (Much enlarged.) 



burrow in the earth, lined with silk. From this they stealthily 

 creep out, when the sun is shining, to stalk their prey, 

 pouncing upon an unwary fly, and soon overcoming it by 

 means of a bite of their poisonous jaws. It is then carried 

 off to the home burrow and devoured at leisure. 



Good sight is necessary for success in hunting, and the 

 form and arrangement of the eyes is peculiar in this group 

 (Fig. 127). Four small eyes, just above the jaws, look for- 

 wards ; above these, two relatively large eyes gaze out also 



