The last joint or _tarsus_ of the spider’s leg is very different in the two cases. It always terminates in claws—either two or three—so that any species can make some show of climbing where the surface is rough and there is anything to cling to, but to obtain a hold on a polished surface it needs a special contrivance. This takes the form of a pad of curiously modified hairs, called a _scopula_. The hairs are club-shaped, narrow at their stalk and swelling towards the tip, and their clinging power seems to be due to a viscid secretion. The foot of any jumping spider will show this structure well. Epeira has no scopula, and its climbing is always laborious unless it has a thread to cling to, but it is supreme as a rope walker, treading daintily on the most delicate threads, mounting a line “hand over hand” with great agility, and manipulating the silk in its various spinning operations with unerring skill and facility. CHAPTER XIV THE ENEMIES OF SPIDERS When one comes to consider the multitudinous risks to which a spider is exposed during the whole course of its life it seems at first a little surprising that the whole tribe has not long ago been exterminated. Spiders continue to flourish, however, and it is very clear that however careless Nature may be of the individual she is extremely solicitous about the race. The infant mortality among these creatures must be appalling. There is first their cannibalistic propensity to be reckoned with. Newly hatched spiders while still within the cocoon seldom attack each other, but as soon as ever each sets up for itself, no quarter is given. It often happens that members of a brood of sedentary spiders spin their first snares in close contiguity, and if food is scarce they eat one another without compunction. It is said that a few individuals of a brood may be reared to maturity on no other food than their sisters and brothers! The case of the survivor of the “Nancy Bell” in the Bab Ballads would be exceedingly commonplace in the aranead world. We have seen, too, how, on occasion, _Atypus_ will devour her young if they do not leave the nest with due expedition. Then if the weather conditions chance to be unfavourable just at the period of departure from the cocoon broods are liable to perish wholesale, washed away and destroyed by deluges of rain; myriads, too, must be carried out to sea in the course of their ballooning operations, and never come safely to land.