TRAP-DOOR SPIDERS. 201 



tulas are often seen measuring two inclies in the 

 spread." 



Mr. Treadwell was quite as much impressed as Dr. 

 Lanzwert with the heUef that the hite of these spiders 

 is fatal, hut it does not appear that either of these 

 gentlemen have obtained conclusive evidence in sup- 

 port of this allegation. 



I have occasionally been bitten by the trap-door 

 spiders in South France, but have never experienced 

 the slightest subsequent inconvenience, nor was 

 there any trace of inflammation or poisoning about 

 the j)unctures which they made, Mr. Blackwall* 

 has made a very careful set of observations on this 

 head, and has caused some of the largest species of 

 British spiders to bite his finger and wrist until the 

 blood flowed, without the slightest ill effects. He also 

 inoculated himself at the same time with the poisonous 

 secretion of the spider and with that of the wasp ; 

 when the latter wound became extremely painful, 

 while the former Was not perceptibly aggravated. 

 Mr. Black wall obtained the spiders' poison by causing 

 a spider to seize a slip of clean glass with its mandibles, 

 when a small quantity of a liquid showing a slightly 

 acid reaction was deposited. 



Mr. Treadwell informed me that these Californian 

 trap-door spiders leave their nests in the daytime, 

 and may be seen walking by the roadside, though 

 they are always prepared to hurry back to their nests 

 on the approach of danger. 



I received the spider which I have represented at 



* Mr. J. "Rlackwall, Pieaearches in Zoologij, ed. 2, 1873 ; clvipter on '' The 

 Poison of the AranciJea," pp. 240-266. 



