60 



which, like the mermaids and sea-nymphs of fable, she resides in comfort and sfecurity. 

 The following is her process. First she spins loose threads in various directions attached 

 to the leaves of aquatic plants, which may be called the frame-work of her chamber, and 

 over them she spreads a transparent varnish resembling liquid glass, which issues from the 

 middle of her spinners, and which is so elastic that it is capable of great expansion and 

 contraction : and if a hole be made in it, it immediately closes again." 



The next operation — that of filling the nest with air — is thus described by Mr. Bell 

 (Journal of the Linna?an Society) : " After the nest has been made as large as half an 

 acorn, she goes to the surface, and returns (in the instance observed, as many as fourteen 

 times successively), and each time brings down a bubble of air which she lets escape into 

 her nest. The bubble is held by the spinnerets and two hind-feet, which are crossed over 

 them, and is obtained in the following manner : — The spider climbs" up on threads or plants 

 nearly to the surface, and puts an end of the abdomen out of water for an instant, and then 

 jerks it under, at the same time crossing the hind legs quickly over it. She then walks 

 down the plants to her nest, opens her hind-feet, and lets the bubble go." 



To go on with Kirby and Spence's account : — " In about a quarter of an hour she has 

 transported as much air as suffices to expand her apartment to its intended extent, and 

 now finds herself in possession of a little aerial edifice, I had almost said an enchanted 

 palace, affording her a commodious and dry retreat in the very midst of the water. Here she 

 reposes unmoved by the storms that agitate the surface of the pool, and devours her prey 

 at ease and in safety. Both sexes form these lodgings. At a particular season of the year 

 the male quits his apartment, approaches that of the female, enters it, and enlarging it by 

 the bubble of air that he carries with him, it becomes a common abode for the happy pair. 

 The spider which forms these singular habitations is one of the largest European species, 

 and in some countries is not uncommon in stagnant pools." 



The water-spiders run about on aquatic plants and catch the insects which live among 

 them. They lay their eggs in the nest, and the young come out and spin little nests of 

 their own, as soon as they are big enough. The hairs, with which their bodies are covered, 

 keep the skin from becoming wet as they go through the water ; and in the nest, which is 

 like a diving-bell, they are as dry as if it were under a stone, or in a hole on dry land. 



The Rev. J. G. Wood states that the water-spider " is a tolerably common species in 

 England, being especially fond of inhabiting quiet and rather deep ditches, when it is well 

 sheltered, and the stream is not rapid enough to endanger the security of its domicile. It 

 is necessary that the water-plants to which the nest is fixed should be sufficiently firm to 

 prevent the nest from being swayed to one side, as, in that case, the air would escape, 

 and the water make its entrance. Owing to the vast number of these spiders that have 

 been sent to the London markets — where they are sold to those who possess fresh-water 

 aquaria — the species is not now nearly so plentiful as used to be the case, and, indeed, it 

 has been almost extirpated from several localities where it was formerly seen in great 

 numbers." 



10. — Trap-Door Spiders. 



Comparatively little was known about these very curious spiders until the publica- 

 tion of Mr. Moggridge's very interesting work, in which he records with great minuteness 

 the observations he made in the south of France. 



The following illustration, Fig. 27, represents the principal kinds of nests that 

 these spiders construct. The most northern genus of this family, Atypus, makes a strong- 

 silken tube, part of which forms the lining of a hole in the ground, and part lies above the 

 surface, among stones and plants, Fig. 27, A. The mouth of the tube is almost always 

 closed, at least when the spider is full-grown. 



Another genus, which lives in warm countries, makes tubes lined with silk and closed 

 at the top by a trap-door. A common species in California, Cteniza Calif omica, is 

 brought thence by travellers. It digs its hole in a fine soil that becomes, when dry, 

 nearly as hard as a brick j but the spider probably works when the ground is wet. The 

 holes are sometimes nearly an inch in diameter, and vary in depth -from two or three 

 inches to a foot. The mouth is a little enlarged and closed by a thick cover that fits 



