INTRODUCTION. 
7 
whose duration is regulated principally by the temperature and moisture of the atmosphere. 
The moult invariably takes place in the cocoon or general envelope of the eggs, and the young 
spiders do not quit this common nest till the weather is mild and genial. They then commonly 
disperse; but the young of some species continue to live together for a considerable time, and 
in many instances are supplied with sustenance by the mother. On deserting the cocoon the 
Lycosce attach themselves to the body of their parent, who carries them with her till they are 
able to provide for themselves. 
Before they arrive at maturity spiders change their integument several times ; the manner 
in which these moults are effected may be illustrated by describing the proceedings of an 
individual of the species Epeira calophylla. Preparatory to casting its integument, this spider 
spins some strong lines in the vicinity of its snare, from which it suspends itself by the feet 
and a filament proceeding from the spinners. After remaining for a short time in this 
situation, the coriaceous covering of the cephalo-thorax gives way laterally, disuniting at the 
insertion of the legs and falces; the line of separation pursues the same direction till it extends 
to the abdomen, which is next disengaged; the extrication of the legs being the last and 
greatest difficulty the spider has to overcome. As the suspensory filament connected with 
the spinners of the exuviae is considerably shorter than the legs, and does not undergo any 
sensible alteration in length, the abdomen, during the process of moulting, becomes gradually 
deflected from its original horizontal direction till it assumes a vertical position nearly at right 
angles with the cephalo-thorax. By this change of posture, attended with numerous 
contortions of the body, and alternate contractions and extensions of the limbs, the spider is 
ultimately enabled to accomplish its purpose. When it has completely disengaged itself from 
the slough, it remains for a short period in a state of great exhaustion, suspended solely by a 
thread from the spinners connected with the interior of the abdominal portion of the cast 
skin, which is much corrugated. After reposing a little, the spider further attaches itself to 
the suspensory lines by the claws of the feet, and when its strength is sufficiently restored, 
and its limbs have acquired the requisite degree of firmness, it ascends its filaments and seeks 
its retreat. 1 * 
Recent investigations have established the fact that the number of times spiders change 
their integument before they become adult is not uniformly the same as regards every species, 
Epeira calophylla having been observed to moult five times, and Teyenaria civilis nine times, 
from the period of their extrication from the egg till they arrived at maturity, and young 
spiders infested by the larva of Polysphinda carbonaria, an insect belonging to the family 
Ichneumonidce, which feeds upon their fluids, never moult. 3 
Like animals of the class Crustacea , spiders possess the property of reproducing such 
limbs as have been detached or mutilated, and this curious physiological phenomenon is 
intimately connected with the renovation of the integument, for legs, palpi, and spinners, which 
have been amputated are observed to be restored, and afterwards to have their dimensions 
enlarged, at the period of moulting only. 3 
1 f Transactions of the Linnean Society/ vol. xvi, pp. 482-484. 
3 ' Report of the Fourteenth Meeting of the British Association for the Advancement of Science,’ 
pp. 70, 71. 
3 Ibid., pp. 71-74. 
