THREAD-SHOOTING ORGANS. 33 



highly curious organs known as the filiferous capsules. 

 They are in this case very minute, heing about one 

 twelve hundredth part of an inch in length, almost 

 linear, and slightly curved. The pressure being con- 

 tinued, each of these little organs suddenly shoots 

 forth from one end to a great length, a slender^ 

 highly elastic thread, which had hitherto been coiled 

 up spirally within its cavity. The expulsion of this 

 thread is effected by a proper organism, excited by 

 the pressure on the tissues of the tentacle, but not 

 forced out by the compression of the capsule itself, for 

 this is much too minute to be compressed by the glass 

 plates, under any power that can be brought to bear 

 upon them. It is supposed that the adhesive touch 

 of the tentacles resides in these little organs, and that 

 a poisonous fluid accompanies the emission of the 

 thread ; since the mere contact of a tentacle with any 

 small animal appears at once to paralyse it, however 

 lively it may have been but a moment before. If this 

 be so, what a highly curious example is here of the 

 wondrously effective provision which the infinite re- 

 sources of the Divine Wisdom have made for the 

 wants of every creature ! We shall have further occa- 

 sion to speak of these curious organs, and to exhibit 

 them under forms even much more complicated and 

 wonderful than they appear here. 



PETIT TOR POOLS. 



The north side of the limestone promontory of Petit 

 Tor, — that side that bounds the little cove where 

 Woodley cuts the great blocks of variegated marble 



