80 



AMERICAN SriDERS AND THEIR SPINNINGWORK. 



Pig. 43. Section view 

 of cocoon of Argiope 

 cophinaria. fe, flossy 

 envelope Inside the 

 outer case, oc ; p.d, 

 the brown padding; 

 c.u, the cup or dish 

 against which the 

 eggs (e) are deposited; 

 c.a, cap covering the 

 egg cup ; c.s, suspen- 

 Kou cord. 



(Figs. 43, 44, o.c) is usually a thin, stiff, parchment like substance, that 

 feels dry, and crackles vinder the touch, as though glazed. It is substan- 

 tially water tight. I have found several cocoons of a softer 

 material, and thicker, much like a delicate yellow felt. 

 Tlie glazing above mentioned is not the result of ageing 

 or M-eathering simply, but is produced by the action of 

 the spider herself, perhaps by the overspreading of the 

 viscid secretion which forms the beads on the spirals of 

 a snare. 



When this outer case is cut away there is first pre- 

 sented a flossy envelope (f.e) of soft yellowish silk, which 

 quite surrounds the contents of the bowl. Next is a dark 

 brown pyriform or spherical pad of spinningwork (p.d), 

 which swathes the eggs completely, interposing a thick, 

 warm, silken blanket between them and the external case. 

 On the upjser part of this pad is a plate or cup (c.u), of 

 like color and closer texture, with the concavity down- 

 ward. I have at least once found this to be a whitish 

 disk of stiff silk. The neck or stalk (nk) of the cocoon 

 is filled with a compact silken cone (c.s), of a yellowish or brown color, 

 which is united at the base to the egg plate (c.u), and at the top terminates 

 in a strong twisted cord (c.s), which sometimes extends upwards and forms 

 the central support to the cocoon. Next to the brown pad is often a thin 

 flossy envelope, which surrounds the egg sac. 

 The latter is a ratlier closely si^un pouch of 

 variable tenacity, and whitish or pinkish 

 white color, that encloses the thousand or 

 more eggs which lie in a globular mass with- 

 in the heart of the cocoon. The inner egg 

 sac (e) is attached above to the plate or cup 

 (c.u), which, after the spiderlings hatch, is 

 pushed upward by them not unlike a traj)- 

 door, permitting them to creep out into the 

 surrounding padding, leaving their white 

 shells within the sac. 



The plate serves to support the eggs, which 

 are probably oviposited upward against it. 

 One female, confined within a box, got so far 

 in the construction of her cocoon as to spin 

 the plate, but went no farther, leaving, how- 

 ever, this evidence of the point at which her ovipositing would have begun. 

 The genus Argiope is widely distributed throughout the globe, and the 

 cocooning habit of the species has elsewhere the same characteristics as in 

 America. Argiope fasciata of Southern Europe and Northern Africa makes 



Fig. -H. Cocoon of Cophinaria dissected 

 to show the parts. Letters as in Fig. 43. 



