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 

 s P itler at ner last moult merely develops the genital aperture 



turity. w ^ tn * ts externa l processes. Up to this time the aperture \a 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 differs 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 mevia, 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 within which they domicile, so that after a cocoon has 

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

 ning work. 



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. 1 



;V~. A cocoon of Epeira cornigera, taken in April and having the 



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



May 15th. A female Epeira 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 Argiope cophinaria in the early winter, and 

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

 silken fibres of the interior enswathment, 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 

 the season is sufficiently advanced to make their egress safe. 



1 Proceedings American Academy of Arts and Sciences, Vol. VII., I860, page 56. 



