SPIDERS 129 



usually terminate in a small, hooked claw, and are used as a 

 pair of extra hands for grasping prey or carrying cocoons. In 

 the male spider the pedipalpi end in curious club-like processes 

 which function as sexual organs. 



The jaws or fakes (chelicerce) are two-jointed, and consist of 

 a base, which sometimes contains the poison gland, and the fang, 

 which is hook-like and can be folded back upon the base like a 

 clasp-knife. Near the tip of the fang is a small orifice leading 

 to the poison gland, through which the poison is ejected into 

 the spider's victim. The poison gland may be situated wholly 

 or partially within the base of the jaw, or may be in the cephalo- 

 thorax and connected by a narrow duct with the opening in 

 the fang. 



Spiders possess from two to eight simple eyes or ocelli, the 

 usual number being eight. These are situated in the fore part of 

 the cephalothorax, and usually arranged in two transverse rows. 

 In some species the eyes are mounted on a slightly raised plat- 

 form, enabling the spider to keep a look out in several directions 

 at the same time. In spite of the number of their eyes, spiders as 

 a rule are by no means keen-sighted, and depend more often upon 

 their sense of touch than on their powers of vision. 



At the end of, and just beneath, the abdomen the spider carries 

 her spinnerets. These are normally six in number, usually 

 arranged in the form of a rosette. Mounted on each of the spin- 

 nerets are a quantity of spinning spools, or tubes, usually from 

 sixty to seventy in number, out of which the silk flows. The 

 spools are connected with the silk glands in the spider's abdomen, 

 in which the silk is secreted in a liquid state, and this fluid, on 

 coming in contact with the air, hardens into a silky thread. The 

 silk glands vary in different families of spiders, reaching the 

 highest state of development in the Orb-weavers, which possess 

 an extraordinary number ; the big Garden spider (Epeira dia- 

 demata) has nearly seven hundred. The silk secreted in these 

 glands is not all of the same quality, and the spider, by using 

 different sets of glands, is able to vary the texture and colour of 

 her threads to suit the particular kind of Work upon which she 

 happens to be engaged. Spiders vary in their spinning powers 

 to a very great degree, some weaving the most finished and 

 ingenious snares, others but rough and rudimentary webs. Some 

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