Limbs which the animal has accidentally lost are renewed at the time of moulting, though their substitutes are at first smaller than those they replace. On the other hand, the struggle to get rid of the old skin sometimes results in the loss of a limb, and the spider is doomed to remain short-handed until the next ecdysis. Until the last moult the generative apertures, which are situated under the anterior part of the abdomen, are completely sealed up. Their disclosure is accompanied, in the case of the male, by a remarkable development of the last joint of each pedipalp, which becomes swollen and often extremely complicated with bulbs, spines, and bristles. A mature male spider may at once be distinguished by the consequent knobbed appearance of its palps; and the particular form they assume is highly characteristic of the species to which the spider belongs. The number of moults, and the intervals at which they occur, no doubt vary with different species. In the case of _Argiope aurelia_, Pollock[269] 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 immediately 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 dispersed group sets up housekeeping on its own account, constructing 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[270] and other naturalists have occasionally described, though social spiders exist (see _Uloborus_, p. 411).