xvii CHATHAM ISLAND 399 



surrounding water, brought here by the great southern Polar 

 current. Excepting during one short season very Httle rain 

 falls, and even then it is irregular ; but the clouds generally 

 hang low. Hence, whilst the lower parts of the islands are very 

 sterile, the upper parts, at a height of a thousand feet and 

 upwards, possess a damp climate and a tolerably luxuriant 

 vegetation. This is especially the case on the windward sides 

 of the islands, which first receive and condense the moisture 

 from the atmosphere. 



In the morning (17th) we landed on Chatham Island, which, 

 like the others, rises with a tame and rounded outline, broken 

 here and there by scattered hillocks, the remains of former 

 craters. Nothing could be less inviting than the first appear- 

 ance. A broken field of black basaltic lava, thrown into the 

 most rugged waves, and crossed by great fissures, is everywhere 

 covered by stunted, sunburnt brushwood, which shows little 

 signs of life. The dry and parched surface, being heated by 

 the noonday sun, gave to the air a. close and sultry feeling, 

 like that from a stove : we fancied even that the bushes smelt 

 unpleasantly. Although I diligently tried to collect as many 

 plants as possible, I succeeded in getting very few ; and such 

 wretched-looking little weeds would have better become an 

 arctic than an equatorial Flora. The brushwood appears, from 

 a short distance, as leafless as our trees during winter ; and it 

 was some time before I discovered that not only almost every 

 plant was now in full leaf, but that the greater number were in 

 flower. The commonest bush is one of the Euphorbiaceae : an 

 acacia and a great odd-looking cactus are the only trees which 

 afford any shade. After the season of heavy rains, the islands are 

 said to appear for a short time partially green. The volcanic 

 island of Fernando Noronha, placed in many respects under 

 nearly similar conditions, is the only other country where I 

 have seen a vegetation at all like this of the Galapagos islands. 



The Beagle sailed round Chatham Island, and anchored in 

 several bays. One night I slept on shore on a part of the 

 island where black truncated cones were extraordinarily 

 numerous : from one small eminence I counted sixty of them, 

 all surmounted by craters more or less perfect. The greater 

 number consisted merely of a ring of red scoriae or slags 

 cemented together : and their height above the plain of lava 



