PE E F A C E. 



His Majesty's ship, Beagle, under the command of Captain 

 FitzRoy, was commissioned in July, 1831, for the purpose 

 of surveying the southern parts of America, and afterwards 

 of circumnavigating the world. In consequence of Captain 

 FitzRoy having expressed a desire that some scientific person 

 should be on board, and having offered to give up part of his 

 own accommodations, I volunteered my services ; and through 

 the kindness of the hydrographer, Captain Beaufort, my appoint- 

 ment received the sanction of the Admiralty. I must here, 

 as on all other occasions, take the opportunity of publicly 

 acknowledging with gratitude, the obligation under which I lie 

 to Captain FitzRoy, and to all the Officers on board the Beagle, 

 for their constant assistance in my scientific pursuits, and for 

 their uniform kindness to me throughout the voyage. On my 

 return (October, 1836) to England, I found myself in possession 



