Mr. F. Pollock on the Epeira Aurelia. 459 



LI. — On the History and Habits of the Epeira Aurelia Spider. 

 By Frederick Pollock, Esq. 



I AM not aware that the history of a spider has ever been written ; 

 and I am therefore induced to give the result of my observations 

 in Madeira, in 1864-65, upon the Epeira Aurelia, which I 

 watched very closely, day by day, for some months. 



The favourite haunt of this spider is the prickly pear — a plant 

 from which its cocoon can scarcely be distinguished in colour, 

 and so close is the resemblance that, the first time I saw one of 

 these cocoons, I could hardly believe that it was not a withered 

 piece of the cactus to which it was attached. 



This cocoon (which is always made in one night) is composed 

 of an inner, soft, globular covering for the eggs, surrounded by 

 a tough, parchment-like case, about the size and shape of half a 

 small walnut, of a faded light-green colour, and is suspended 

 by a number of threads, stretching out in all directions to the 

 surrounding plants. It is water-tight, and inaccessible to ants, 

 which are almost the only enemies to spiders in the island ; and 

 it contains from about 600 to 1000 bright yellow eggs, glued 

 together in the shape of a bean. 



By cutting several cocoons open, I ascertained that the egg- 

 shells burst at the end of the fourth week. The young spiders 

 are then very helpless, and nearly transparent. At the end of 

 the fifth week they cast ofi* their first skin, and become quite 

 lively and active. 



They are at this time about as large as an ordinary pin's head, 

 of a bright yellow, with darkish legs; and three or four dark 

 spots gradually develope themselves down each side of the abdo- 

 men. At about the end of the seventh week they emerge 

 through a small hole (probably gnawed by them) from their 

 prison, never to return to it. 



They then club harmoniously together, hanging closely packed 

 in a ball, upheld by an infinity of lines which they attach to the 

 adjacent objects. 



For the first ten days or fortnight of their freedom they thus 

 live in amity, occasionally spreading out (probably for ventila- 

 tion), but always, during that time, reverting to the form of a 

 compact cluster, and eating nothing. 



When the fortnight is over, their friendship ceases ; sometimes 

 all of them, and invariably most of them, wander away, a very 

 few remaining behind near their birthplace. 



Hitherto they have merely made lines ; now each individual 

 makes a web for itself, about as large as a penny piece, to catch 

 its neighbour, or any other prey which may come within its 

 clutches. 



