34° ARACHNIDA ARANEAE chap. 



The number of moults, and the intervals at which they occur, 

 no doubt vary with different species. In the case of Arijiope 

 aurdia, Pollock ^ has found that the female moults nine times 

 after leaving the cocoon, the first ecdysis occurring after an 

 interval of from one to two months, according to the abundance 

 or scarcity of food. The subsequent intervals gradually increase 

 from about a fortnight to something over three weeks. 



Behaviour of the Newly-hatched Spider. — The mode of life 

 of a spider just freed from the cocoon will of course vary greatly 

 according to the Family to which it belongs. 



The Epeiridae are the builders of the familiar wheel or orb- 

 web. Spiders of this Family usually remain together on friendly 

 terms for a week or more after leaving the nest. Most of the 

 time they are congregated in a ball-like mass, perhaps for the 

 sake of warmth, but upon being touched or shaken they im- 

 mediately disperse along the multitudinous fine lines which they, 

 have spun in all directions, to reassemble as soon as the panic 

 has subsided. Such a ball of the yellow and black offspring of 

 the large Garden-spider, Epeira diademata, is no uncommon 

 sight in the early autumn, and the shower of " golden rain " that 

 results from their disturbance is not likely to be forgotten if it 

 has ever been observed by the reader. This harmonious family 

 life only continues as long as the young spiders are unable to 

 feed — a period which, in some of the larger species, is said to 

 extend to ten days or a fortnight. 



Individual life then commences, and each member of the dis- 

 persed group sets up housekeeping on its own account, con- 

 structing at the first attempt a snare in all respects similar, 

 except in size, to those of its parent. 



Of course the young Spiders have not migrated far, and a 

 bush may frequently be seen covered by the often contiguous 

 nets of the members of a single brood. This, as Dr. M'Cook 

 thinks, is the true explanation of some of the cases of "gregarious 

 spiders " which Darwin ^ and other naturalists have occasionally 

 described, though social spiders exist (see Ulohorus, p. 411). 



Very similar habits obtain among the Theridiidae, or line- 

 weaving spiders, a familiar example of which is the pretty little 

 Theridion sisyjphium, whose highly-irregular snare may be found 

 on any holly bush during the summer months. 



' Ann. Nat. Hist. (3), xv., 1865, p. 459. '^ Voyage of the Beagle. 



