214 



AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



First 

 Days of 

 Outdoor 

 Life. 



Tubeweavers, and Laterigrades, especially, have been studied. The results 

 from experimental hatching are but little different from those which 

 everywhere transpire in Nature, and, taken together witli numerous facts 

 noted afield, enable us to accurately sketch the life of the infant spider 

 just after deliverance from the cocoon. 



One example, followed consecutively, will illustrate the habits of Orb- 

 weavers. Early in May a cocoon of Epeira insularis was taken from a 

 tree on the banks of the Schuylkill. It had been placed by 

 the mother spider on the under side of a branch, where it 

 was best protected from the weather, and consisted externally 

 of a ball of thick, yellow, curled floss, about one-half an inch in 

 diameter. (Fig. 245, C.) This was attached to the limb by a 

 thin coating of white tissue, from which short, strong cords entered the 

 ball. Within the ball were about one hundred young spiders, just fully 

 hatched. The cocoon was placed in a paper box, and the spiderlings re- 

 mained shut up in it until May 13th. Meanwhile they had made their 

 first moult. This cocoon was now opened and jjut within a large covered 

 paper box, which, by a dent in the side, had free communication with 



the outside. Next morning I found that 

 the spiderlings had issued from the box 

 and M'oven a mass of delicate webbing 

 over the surrounding objects upon the 

 taljle. The lines were most closely spun 

 near the points of exit, where they re- 

 sembled a delicate tissue web. They were 

 carried along the table on one side to 

 a distance of five feet, on another of 

 two feet, and the lines decreased in number as the distance increased. 

 Where threads were dense the spiderlings were massed (O, Fig. 246) in 

 large numbers, and as the lines thinned out the numbers decreased, until 

 at each of the two points where the spinningwork ceased were one or two 

 pioneers engaged in pushing the lines further from the centre. 



In point of fact, this last sentence expresses the general instinct which 

 controls the young on their first issue from the cocoon — they spin away, 

 and away from the home cradle, restlessly further and further, until they 

 are arrested by satisfactory surroundings and further flight is hindered, 

 or until they pause to undergo another moult. This is undoubtedly the 

 impulse bestowed by Nature for the dispersion of the brood, 

 Distribu- y;[i\^ a, view to the distribution and preservation of the sjiecies, 

 g . primarily, perhaps, to the preservation of the young from their 

 own cannibal propensities. In order to test this matter and de- 

 cide the mode of procedure, I fixed attention upon one of the outposts. 

 Three feet from the main assembly (0, Fig. 246) a single straggler had 

 carried or followed a line. 



Fig. 245. Cocoon (C) of Insular spider, on 

 the under side of a twig. 



