208 THE VOYAGE. .ETAT. 23. [1832. 



C. Darwin to J. S. Hensloiu. 



Rio de Janeiro, May 18, 1832. 



My dear Henslow, 



% % X •& * 



Till arriving at Teneriffe (we did not touch at Madeira) 

 I was scarcely out of my hammock, and really suffered more 

 than you can well imagine from such a cause. At Santa 

 Cruz, whilst looking amongst the clouds for the Peak, and 

 repeating to myself Humboldt's sublime descriptions, it was 

 announced we must perform twelve days' strict quarantine. 

 We had made a short passage, so " Up jib," and away for St. 

 Jago. You will say all this sounds very bad, and so it was ; 

 but from that to the present time it has been nearly one scene 

 of continual enjoyment. A net over the stern kept me at full 

 work till we arrived at St. Jago. Here we spent three most 

 delightful weeks. The geology was pre-eminently interest- 

 ing, and I believe quite new ; there are some facts on a 

 large scale of upraised coast (which is an excellent epoch for 

 all the volcanic rocks to date from), that would interest Mr. 

 Lyell. 



One great source of perplexity to me is an utter ignorance 

 whether I note the right facts, and whether they are of suffi- 

 cient importance to interest others. In the one thing collect- 

 ing I cannot go wrong. St. Jago is singularly barren, and 

 produces few plants or insects, so that my hammer was my 

 usual companion, and in its company most delightful hours I 

 spent. On the coast I collected many marine animals, chiefly 

 gasteropodous (I think some new). I examined pretty accu- 

 rately a Caryopfiyl/ea, and, if my eyes are not bewitched, 

 former descriptions have not the slightest resemblance to the 

 animal. I took several specimens of an Octopus which pos- 

 sessed a most marvellous power of changing its colours, equal- 

 ling any chameleon, and evidently accommodating the changes 

 to the colour of the ground which it passed over. Yellowish 

 green, dark brown, and red, were the prevailing colours ; this 

 fact appears to be new, as far as I can find out. Geology and 



