CHAP, xiv ARANEAE MOULTS 339 



The first moult takes place while the newly-hatched spider is 

 still with the rest of the brood either in or close to the " cocoon " 

 or egg-bag. M'Cook l thus describes the conclusion of the opera- 

 tion in the case of Agdena naevia : 



" While it held on to the flossy nest with the two front and 

 third pairs of legs, the hind pair was drawn up and forward, and 

 the feet grasped the upper margin of the sac-like shell, which, 

 when first seen, was about half-way removed from the abdomen. 

 The feet pushed downwards, and at the same time the abdomen 

 appeared to be pulled upward until the white pouch was gradually 

 worked oft'." 



The later moults are generally accomplished by the spider 

 collecting all its legs together and attaching them with silk to 

 the web above, while the body, also attached, hangs below. The 

 old skin then splits along the sides of the body, and the animal, 

 by a series of violent efforts, wriggles itself free, leaving a com- 

 plete cast of itself, including the legs, suspended above it. For a 

 day or two before the operation the spider eats nothing, and im- 

 mediately upon its completion it hangs in a limp and helpless 

 condition for a quarter of an hour or so, until the new integu- 

 ment has had time to harden. It is not unlikely that the reader 

 has mistaken these casts for the shrivelled forms of unlucky 

 spiders, and has had his sympathies aroused, or has experienced 

 a grim satisfaction, in consequence an expenditure of emotion 

 which this account may enable him to economise in future. 



Limbs which the animal has accidentally lost are renewed at 

 the time of moulting, though their substitutes are at first smaller 

 than those they replace. On the other hand, the struggle to get 

 rid of the old skin sometimes results in the loss of a limb, and the 

 spider is doomed to remain short-handed until the next ecdysis. 

 * Until the last moult the generative apertures, which are 

 situated under the anterior part of the abdomen, are completely 

 sealed up. Their disclosure is accompanied, in the case of the 

 male, by a remarkable development of the last joint of each 

 pedipalp, which becomes swollen and often extremely compli- 

 cated with bulbs, spines, and bristles. A mature male spider 

 may at once be distinguished by the consequent knobbed appear- 

 ance of its palps ; and the particular form they assume is highly 

 characteristic of the species to which the spider belongs. 

 1 American Spiders and their Spinning Work, ii., 1S90, p. 208. 



