TRAP -DOOR SPIDERS. 123 



two doors is discoloured and partly decayed, this 

 being, no doubt, the one which had been buried be- 

 neath in the earth and so rendered useless. 



Questions have often been asked as to the manner 

 in which trap-door nests are commenced in the first 

 instance, and whether the weaving of the silk lining 

 is begun at the top or the bottom of the tube. 



The structure of the cork door also, which often 

 appears so perfectly turned as to resemble the work 

 of a potter's lathe, is another difficulty. 



These questions have, as it seems to me, been 

 needlessly complicated by taking it for granted that 

 the perfect nest of the mature spider is made all at 

 one time, that the tube, perhaps of a foot in length, 

 is excavated, lined, and furnished with a door within 

 some short period of time, such as ten days or a 

 fortnight, perhaps. 



On the contrary, I believe that the nests are, as a 

 rule, the result of many successive enlargements, and 

 that the nest of the infant, the tube of which is no 

 bigger than a crowquill, is not abandoned, but be- 

 comes that of the full-grown spider. This must 

 require time, but how long, whether months or years, 

 we have yet to learn. 



Very little is known at present as to the longevity 

 of spiders, but Mr. Blackwall* says that some live 

 only one year, while others, such as Tegenaria civilis 

 and Segestria senoculata, have been known to live four. 



Whether the trap-door spiders are very long lived 

 or not I cannot positively sa}^ but, from the appear- 

 ance of the growth of moss and lichen on the doors 



• Spiders of Great Britain and Ireland, p. 8. 



