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OF HARTING. 449 



falces. Each falx consists of a perforated fang, articu- 

 lated to a basal joint, which is itself articulated to the 

 front part of the cephalo-thorax. Each joint has an 

 independent motion of its own, and on the under 

 surface of the basal one there is a longitudinal groove 

 for the reception of the fang, which, when at rest, is 

 bent back into its support, as the blade of an ordinary 

 clasp-knife into its handle. Within each fang is at- 

 tached, near the aperture at its extremity, a very fine 

 thread or duct, which may be traced by careful dissec- 

 tion through the basal joint into the cephalo-thorax, 

 where it terminates in a poison-bag and gland. There 

 is, therefore, no internal passage between the falces 

 and oesophagus or the stomach, through which any 

 portion of food could be conveyed to the latter, so 

 that, contrary to popular belief, the falces are certainly 

 not instruments of suction. It would appear that their 

 office is to seize and disable the prey, which they sub- 

 sequently retain in their fatal grasp until the maxillae, 

 which are within the mouth, have acted upon it to the 

 owner's satisfaction. 



The eyes of spiders are situated on the upper surface 

 of the cephalo-thorax, just behind the falces, and their 

 positions, relatively to each other, are so uniform in 

 closely allied species, that their mode of arrangement 

 is an important generic character in the system of a 

 well-known arachnologist 



The external spinning apparatus is at the extremity 

 of the abdomen on the underside, and consists of four 

 or six nipple-like processes or spinners, each of which 

 is furnished with numerous minute tubes or spinnerets, 

 very thickly distributed over the whole of its exterior 

 surface, and a central aperture at the apex. From 

 these spinners and spinnerets issues, at the will of the 

 animal, a viscid secretion, which at first adheres to any 

 surface against which it may be pressed, and subse- 

 quently dries up in the form of a thread, almost as 

 rapidly as it is drawn out. As many as a thousand 



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