COCOON LIFE AND BABYHOOD. 207 



called, and the curious and more or less complete congeries of lobes, bulbs, 

 and spines known as the palpal organs. The full dimensions of the legs 

 are also sometimes attained at the same period. The female 

 °^fj^^ spider at her last moult merely develops the genital aperture 

 turity. ^'^'^ ^^^ external processes. Up to this time the aperture is in- 

 visible, though, like the palpal organs of the male, it has been 

 gradually developing beneath the cuticle. 



II. 



Of spider life within the cocoon our knowledge must necessarily be 

 limited. The period of hatching diifers according to the species, the time 

 of the year, and the nature of the season. The eggs in many 

 . .„ autumn cocoons do not hatch until spring, say from the middle 



of April to the middle of May. I have gathered many cocoons 

 that have wintered out of doors, of Agalena najvia, of various Laterigrades, 

 and several species of Orbweavers, which contained unhatched eggs from 

 which young spiders were subsequently bred. After hatching, the little 

 creatures remain massed within the cocoon along with the white shell of 

 the egg or the first moult. At times they spin delicate threads, which add 

 to the flossy nest witliin which they domicile, so tliat after a cocoon has 

 been opened for examination, the fracture will be closed up by such spin- 

 ningwork. 



The spring or summer cocoons are hatched at periods varying from 



fifteen to thirty days. According to Professor Wilder, the eggs of Nephila 



plumipes laid in September were hatched in about thirty days.' 

 Period of . c t^ ■ ■ ^ i -am -, ■, ■ \^ 



„ , , . A cocoon or ii,pcu-a cornigera, taken in April and having the 



eggs then unhatched, I found to contain fully hatched young on 



May 15th. A female Epcira sclopetaria cocooned in a trying box May 



26th, and on June 13th, eighteen days thereafter, the young brood issued 



from the cocoon. 



I have opened cocoons of Argiopo cophinaria in the early winter, and 



found the young within crawling about in a sluggish way among the 



silken fibres of the interior ensvvathment, or massed inside the central, 



common pouch along with the white skins of their first moult. On the 



contrary, I have found cocoons in which, as late as April 20th, the young 



had just cast off the egg shell, and were beginning their first, feeble 



movements in struggling with the silken lines of their enswathment. I 



have little doubt that the young of Argiope are generally hatched from 



the egg within a month or six weeks after the cocoon has been made. 



They, therefore, remain within the cocoon during the winter and until 



tlie season is sufficiently advanced to make their egress safe. 



' ProceeJ info's .\inerican AciuU^iiiy of .'Vits and Scienci's, Vol. VII., 1800, page 5C. 



