MASON SPIDERS. DIVING SPIDERS. 137 



and of Southern Europe, which to the mouth of its retreat (an 

 excavated subterranean cell, tapestried with silk), contrives to 

 adjust an earth-kneaded door, hung upon a silken hinge, and 

 self-closing with an elastic spring, after each entrance and 

 exit of the cavern's occupant. 



For description in full of this foreign master-piece of 

 Arachnean architecture we must refer to other pages,"* and 

 pursuing the main purpose of our own, invite attention to 

 the constructive skill of one more native Spider. 



Who has not seen, or is not curious to behold that "lion'' 

 of the Polytechnic, the diving-bell? Now those who for lack of 

 opportunity are among the latter, may see a diving-bell in mina- 

 ture by repairing to the brink of some running stream, canal, 

 or ditch (provided it be not stagnant), in the neighbourhood of 

 London or elsewhere. There they may perceive, shining through 

 the water, a little globe apparently of silver, which surrounds, as 

 with a garment, the body of a Diving Spider, f whose submerged 

 habitation and curious economy have been described, as follows, 

 by different observers. " These Spiders," says De Geer, " spin in 



the water a cell of strong closely woven white silk, in the form 







of a diving-bell or half a pigeon's egg. This is sometimes 

 quite submerged ; at others partly above the water, and is 

 always attached to some objects near it by a number of 

 irregular threads. It is closed all round, but has a large 

 opening below, which however I found closed on the 15th of 

 * See Insect Architecture. f Diving Water-Spider, Argyroneta aquatica. 



