74; INTRODUCTION. 



the world a rocky and partially-protected shore perhaps 

 supports, in a given space, a greater number of individual 

 animals than any other station. There is one marine pro- 

 duction which from its importance is worthy of a particular 

 liistory; it is the Kelp, ov Macrocf/stis pi/rifera. This plant 

 grows on every rock from low-water mark to a great depth, 

 both on the outer coast (of Tierra del Fuego) and within 

 the channels. I believe, during the voyages of the Adventure 

 and Beagle, not one rock near the surface was discovered, 

 whicli was not buoyed by this floating weed. The good 

 service it thus affords to vessels navigating near this stormy 

 land is evident ; and it certainly has saved many a one 

 from being drowned. I know few things more surprising 

 than to see this plant growing and flourishing amidst those 

 breakers of the AYestem Ocean, which no mass of rock, let 

 it be ever so hard, can long resist.^^ Though the stem of 

 this plant is not above an inch in diameter, it is of great 

 strength and surprising longitude. Captain Cooke says that 

 some of it grows to the length of 360 feet and upwards. 

 And yet it is much surpassed in this respect by another. 

 If UrviUaa idilis, I think, which grows to the amazing length 

 of 1500 feet. Mr. Darwin adds : — "^Thc number of living 

 creatures of all orders whose existence intimately depends 



