Professor Henslow's interest in his young pupil's progress is shown by the fact that in 1835 (December 1) he printed some extracts from his letters, for distribution among the members of the Cambridge Philosophical Society, in consequence of the notice excited by some geological observations they contained, which had been read before the society on the 16th of November previous. The following points having a personal reference to the traveller may be quoted. On August 15, 1832, Darwin wrote from Monte Video, "I might collect a far greater number of specimens of invertebrate animals if I took up less time over each: but I have come to the conclusion that two animals with their original colour and shape noted down will be more valuable to naturalists than six with only dates and place." Here we see the accuracy which was the source of much of his after-success. On November 24, 1832, he writes from the same place, "As for one little toad, I hope it may be new, that it may be christened 'Diabolicus.' Milton must allude to this very individual, when he talks of 'squat like a toad.'" In March, 1834, writing from East Falkland Island, he says, "The whole of the east coast of the southern part of South America has been elevated from the ocean since a period during which mussels have not lost their blue colour." Describing his examination of the central peaks of the Andes in Chili, he says, April 18, 1835, "I cannot tell you how much I enjoyed some of these views; it is worth coming from England, once to feel such intense delight. At an elevation of from ten to twelve thousand feet, there is a transparency in the air, and a confusion of distances, and a sort of stillness, which give the sensation of being in another world." Coming now to Darwin's Journal as first published in 1839, forming the third volume of Fitzroy's narrative, the 7th of January, 1832, on which the Peak of Teneriffe was seen suddenly illumined, while the lower parts were veiled in fleecy clouds, is noted as "the first of many delightful days never to be forgotten." On the 16th the Cape de Verde Islands were reached, and their volcanic geology was carefully explored. Darwin was already equipped with the first volume of Lyell's famous "Principles of Geology," published in 1830, the second following in 1832; and in the second edition of his journal, published in 1845, he acknowledges with grateful pleasure "that the chief part of whatever scientific merit this journal and the other works of the author may possess, has been derived from studying the well-known and admirable 'Principles of Geology.'" He was already noting the diffusion of minute organisms and impalpable dust by winds,[4] and was much surprised to find in some dust collected on a vessel 300 miles from land particles of stone more than a thousandth of an inch square. After this, he remarks, one need not be surprised at the diffusion of the far lighter and smaller sporules of cryptogamous plants.