PART II -MATERNAL INDUSTRY AND INSTINCTS. 



CHAPTER IV. 

 MATERNAL INDUSTRY : COCOONS OF ORB WEAVERS. 



The maternal industry of sijiders is concerned chiefly in the preparation 

 of the silken sac within which the eggs are deposited. It includes also tlie 

 various methods by which this sac, when woven, is disposed of in order 

 to secure a greater protection for its contents from exigencies of climate 

 and weather, and assaults of enemies. I shall treat this part of my subject 

 after the methods previously adopted, and describe in detail the cocooning 

 habits of Orb weavers, and then present brief studies of the cocoonery of 

 typical species of other tribes, witli a view to comparison as to various 

 jjoints, such as the form, number, modes of preservation, and construction. 



I. 



Among Orbweavers, the largest cocoon known to me is that of Basket 

 Argiope. It is usually a pyriform or globular flask or sac of stiff, parch- 

 ment like, yellowish silk, suspended in various sites by a series 

 Argiope's ^^ ^j^^^,^ ^inQs passing from all parts thereof to surrounding ob- 

 jects. These lines, at the points of attachment to the cocoon, 

 diverge into minute conical or pyramidal deltas, similar to those formed to 

 anchor the usual dragline when the spider walks. 



The objects upon which the cocoons are hung depend, of course, upon 

 the local habitat of the individual. For the most part, Argiope spins her 

 web in low positions; on the tall grasses growing in the angles of a rail 

 or "worm" fence; on the miscellaneous shrubbery that will be seen along 

 the edge of a New England stone fence ; in the low l)uslies of various sorts 

 found in fields, lanes, the skirts of woods, and out of the way places— one 

 will be sure to meet these pear shaped objects in October or early November. 



A collection that lies before me as I write will be sufficiently tyi)ical 

 of the positions in which Argiope spins her cocoons. Here is a cluster of 

 tall grasses, upon which two cocoons are hung. One, with a brown 

 Cocoon- external case, is suspended within a series of closely intersecting 

 mg 1 es. ygj^Q^jgj-^ threads, which are lashed to the stalks of the grass 

 eight inches from the roots. Just within the little concavity formed by the 

 stems as they have been pulled together in a circular position, the little 



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