There is little doubt that this book was one of the most potent factors in determining the bent of Darwin's mind. His entire educational experience had failed to appeal to him. It is fortunate, we now know, that this was the case. If the university course of the time had really seized him it would have made but one more student like hundreds it was turning out each year. For most of us this is the happy event. Now and then comes the rare spirit to whom all of this fails to appeal because he is ready for something better. Such was the spirit of Charles Darwin. He started on his journey with a mind singularly free from prepossessions. In the long hours of this sailing voyage across the Atlantic Ocean Darwin had time to read and ponder Lyell's weighty words. By the time he reached the Brazilian shore he was filled with Lyell's conception that the present is the child of the past, developing out of it in orderly sequence. Lyell expressly denied that this is true of the animal and plant world. He applied it only to the face of the earth, with its mountains of uplift and its valleys of erosion. But the underlying principle of an orderly development under the action of natural causes was there. In Darwin's mind this at once found acceptance, and was destined to a fruition its author had expressly disclaimed. The narrative of this voyage, as subsequently written, describes the islands visited by the _Beagle_ in crossing the Atlantic Ocean. The contrast between the simple and general interest in these islands and the care with which Darwin described the Galapagos and the Keeling Atoll visited later in the voyage are speaking evidence of the rapid development going on in the mind of the young naturalist. Reaching the shore of South America, Darwin first turns to its geology. But before long the animal life attracts his attention. In the Brazilian forest Darwin had his first experience of the wealth of animal and plant life in the tropics, and, like all naturalists, he was very enthusiastic over it. Among the animals that particularly attracted his attention was the sloth, a peculiar creature climbing slowly about the trees, small of size and sluggish of habit. Another animal that interested him greatly was the little armadillo with its interesting habit of curling up in its plated skin.