326 



AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



spinnerets, not interwoven with them. When a sufficient number has been 

 laid upon the original frame, by the repeated spinning and beating action 

 of the spider, the whole presents the appearance of a thickened sheet 

 wrought into the form of a tube. (Fig. 310.) 



I have observed the overspinning of an under- 

 ground burrow by a Purseweb in a glass jar. The 

 same method was followed, except that the frame lines 

 were spun against the concavity of the 

 burrow and the inner surface of the glass. 

 The spider then proceeded to thicken 

 over the frame by spinning against it lit- 

 tle ribbons of silk and beating them down 

 with her long spinnerets. When hang- 

 ing head downward, with claws clasping 

 the frame lines, and spinning upward 

 against the roof of her burrow (Fig. 312), 

 she presented to the observer a rather 

 odd appearance. No doubt this is the 

 mode by which the spider silklines the 

 underground part of her tubular snare 

 FIG. 311. Purseweb spider's nest, view below which extends beneath the sand some- 



ground, as well as above The subterranean timeg ag f ap &g aboye the gur f ace 

 terminus is expanded and branched. 



either single, or branched, after the man- 

 ner represented in Fig. 311. (See also Fig. 303.) 



The same method of spinning is used by our American tarantula, Eu- 

 rypelma hentzii, in weaving the rug upon which it often loves to stay 

 when in artificial confinement. In the act of spinning, the 

 ' r *- i ~ long posterior spinnerets are curved upward and forward (which 

 is, indeed, an habitual position with this tribe), and from the 

 spinning tubes along the exterior part of the spinneret are given 

 out numerous fine threads. 

 These are pressed to the ground 

 by the downward motion of 

 the spinnerets. The abdomen 

 is then lifted up, and by this 

 action the threads are drawn 

 out. Again the downward mo- 

 tion is repeated, and simulta- 

 neously the end of the abdo- 

 men to which the spinnerets FIG 312 Purgeweb spider working the weft on an 

 are attached receives a lateral underground frame, 



motion that causes the threads to be spread over the surface of the 

 ground. At the same time the animal slowly moves its whole body 

 around, as upon a pivot, thus dispersing the silk over a circular patch of 



