328 AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



species for the different moults of one. These clifficulties are increased by 

 the fact that the adult males and females of a species usually differ con- 

 siderably in appearance.^ 



This is not entirely in accord with the statement of Mr. Cambridge that 

 the pattern of a spider — that is, the design formed by its colors and mark- 

 ings—differs in general but little in immaturity and maturity, excepting 

 that it is usually more distinct in the young and in the female exam- 

 ples. The first of these statements appears to me to be too sweeping, 

 unless the period of youth referred to be placed well on toward maturity. 

 In some species there are striking differences between the colors and mark- 

 ings of the very young spider and those which it attains after one or 

 two changes of skin. Epeira diademata and Zilla x-notata, two of the 

 commonest English spiders, are conspicuous examples of this."^ 



According to Peckham, the young spiders often differ from adults, and 

 in many species when the sexes differ when adult, the male being brighter, 

 they are alike until they reach maturity, when the male, along 

 and Sex ^^*''' ''^^ sexual development, acquires his brilliant color. Again, 

 soon after hatching, young spiders, probably at the third or 

 fourth moult, begin to show color more decidedly, and the colors are dis- 

 tributed in the patterns characteristic of the species, and as the spiders 

 continue to advance in age and make their successive moults, other and 

 more marked changes maybe noted. ^ The truth appears to be that there 

 are differences among si)ecies in the degrees of resemblance between imma- 

 ture and adult forms, but that generally the likeness strengthens from the 

 time of hatching onward to maturity. 



I give a few observations upon the appearance of spiderlings during 

 and shortly after their cocoon life. These, however, can hardly be fully 

 appreciated by those who do not know the adult species, without consult- 

 ing the plates in Volume III. But the following species may bo com- 

 pared with figures or descriptions in this volume. 



.Just after its escape from the egg shell the young of Argiope coph- 



inaria is about two millimetres long. The ccplialothorax is a grayish 



white color, translucent, upon the fore part of which the eyes, 



Appear- ^yiijcji ^^e a brownish color, stand out vividly, seeming to form 



Young. *"■ ^'"'^^ P*"'* °* ^^^^ ^^*^^- '^^^^ l^gs ^'■^ white, translucent, as 

 are also the paljjs ; as the spider sits upon a surface both legs 

 and palps are doubled under the body. In this position the palps seem 

 to be a shorter pair of legs, so that as thus viewed the animal really 

 seems to have ten legs. The abdomen is a yellowish color, except that 

 in the places where the peculiar yellowish irregular marks of the dorsum 

 are seen upon the adult, may be seen irregular markings of pure white. 



' North American Spiders of the Family Attidse, page 5. * gpiders of Dorset, xxvi. 

 ' Peckhams, " Sexual Selection," pages 14, 15. 



