374 



AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



the cocoons of an adult mother, and in the same position upon the orb. 

 These cocoons are also covered with the disjecta membra of minute insects 



killed by the spiderlings. How shall we account for this strange 

 oung i m itation of a maternal habit by the young ? Are these puff 



balls " dummies " ? Is their purpose to deceive assaulting ene- 

 mies, and thus protect their maker? I know no examples of a similar 

 habit, except certain Gasteracanthas, that sometimes spread like objects at 

 various points upon their webs, and a single case of Acrosoma rugosa, 

 whose orb I found to be decorated in like manner. 



Fig. 318 represents Caudata, much enlarged, clinging to a new made 

 cocoon, while two others hang above, covered with the disjecta membra of 

 slain victims. In nature the cocoons are often much more thickly covered 

 than here shown. A slight viscidity of the silken fibre of the sacs evi- 

 dently assists this habit, although the scalpage is tied or lashed to the 

 surface by minute threads. By the time the maternal cares of the spider 

 are ended, if the season be one fruitful of insects, not only all the cocoons, 

 but the connecting parts of the supporting string, will be hung thickly 

 with this ghastly crop. 



Dr. Martin Lister 1 observed the habit in Cyclosa conica, a European 

 species that corresponds closely with our Caudata, of thus stringing the 



debris of its prey along the central vertical line of its snare. In 



attributing the act to a sort of " pride of the chase " (venationis 

 gloriola), he gave a reason perhaps as near the truth as some other theo- 

 ries. It is at least sufficiently startling to find in the habits of an aranead 

 such a striking analogue of the customs of our savage human fellows who 

 decorate their persons, lodges, and villages with the scalps and skulls of 

 the unhappy victims of war and cannibal feasts. I am inclined to believe 

 that the habit is for the most part protective of the young, being intended 

 to guard the egg sac from the assaults of parasitic enemies. If so, it is a 

 convenient substitute for chopped straw, mud, gnawed wood, etc., with 

 which other araneads defend their eggs from enemies. But it has the dis- 

 advantage of depending wholly upon the somewhat uncertain chances of 

 the chase. These chances, however, are the best, and indeed the only ones 

 at her disposal. The habit of suspending her cocoons within her viscid 

 orb well nigh estops her from descending to the ground or adjoining plants 

 to procure dirt or chippage, as species can readily do that attach cocoons 

 to various surfaces. I have seen only one case in which Caudata's cocoons 

 appeared to be daubed with particles of mud. The general and special 

 habits are thus happily harmonized. 



In addition to this the habit may also serve as a protection to the 

 spider herself. At all events, as she hangs at the tip of one of these orna- 

 mented cocoons she is with some difficulty distinguishable from them, 



Scalpage. 



1 Hist. Animal Angl., page 33, 34, Tit. 4. 



