122 AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



again with a thin sheet, upon which the mother overlays a wadding of 

 sawdust or pulverized bark gnawed from the surrounding surface. In 

 the absence of such materials, the upholstery consists of any available 

 fibre furnished by the particular site. The whole is then overspun with 

 an exterior covering. It is thus one of the most elaborate of known 

 cocoons, and apparently is as well calculated to preserve the life concealed 

 within as any spinningwork that could be wrought by aranead spinning 

 organs. 



When Agalena cannot conveniently obtain sawdust and like material for 

 the upholstery of her cocoon, she will overspin her eggs without such pro- 

 tection. For example, a female of this species was observed upon 

 Uphol- j.j ie wm( jow o f a chicken house, with a pretty tubular snare hung 

 , g , against the frame, and two cocoons woven upon the glass near 

 by. These were simply eggs of a pinkish hue, covered over with 

 silken spinningwork and no upholstery added. I have also found Aga- 

 lena's cocoon woven upon the under side of a leaf, in which position it 



contained no upholstery, and, indeed, quite resem- 

 bled the cocoon of an Epei'roid spider spun in 

 like situation. I suppose that in this case, as also 

 in the preceding one, the difficulty of gnawing off 

 the tough, green fibre of the leaf and branches, or 

 'niiJia on lo^sTbark, itTshow ^ the painted wooden frame of the window was an 

 the mode of uniting to the obstacle which prevented the mother from pursu- 



opposite surface by a stalk. . . , . . _ , . , , . 



ing her usual habit. Perhaps, indeed, it requires 



the suggestion of near by and available material, like that of bark or 

 decayed wood, to induce this additional upholstering protection of the 

 cocoon. 



On the other hand, a female of this species, which I kept within a 

 glass jar, having made her cocoon, proceeded to collect from the bottom of 

 the jar bits of debris of various sorts, which she placed upon it in the 

 usual position. There were only a few of these particles, not enough to 

 be of any value for the protection of the enclosed eggs, even if there had 

 been any exposure to danger under the circumstances. Of course, it could 

 hardly have been expected that this mother would understand that her 

 offspring, by reason of the situation within a glass jar, would be safe 

 from the enemies which usually assail the eggs of the species in natural 

 site. 



Sometimes the cocoon of this species, when spun upon a loose piece of 

 bark, will have a thick stalk spun across to the opposite surface of the 

 tree to which it is united by a circular patch of thick silk. (Fig. 129.) 

 A like arrangement is found when the cocoon is woven up against the 

 lower side of a stone, the exterior or under part being then carried down- 

 ward by a stalk to the earth. This is not a common method, however, and 

 I can think of no good reason for such a variation. 



