Wallace became a full-time naturalist in 1848, the year when he and Bates set out on their journey to South America. Wallace was twenty-five at the time and over half of his life had been spent in various parts of Wales, the land of his birth. Commentators have tended to gloss over or ignore any formative influences from this early period of his life or even to dismiss them as non-existent. This is surprising as it was during the eight or so years in Wales leading up to 1848 that Wallace's interest in natural history emerged. ‘The importance of this early period in Wallace's life can scarcely be over-emphasized’ wrote Durant in his account of the development of the Wallace personality, but he omitted any specific reference to the significance of the early period in Wales. Those seeking a simple unitary cause for Wallace's conversion to natural history usually locate this in his visit to Leicester in 1844 and his meeting there with H. W. Bates. ‘The odyssey began … in 1844, in Leicester’ wrote Brooks, adding that ‘the more remote parts of … southern Wales had offered little reading material…’ This, and similar claims, are presumably founded primarily on Wallace's belief—expressed sixty years later—that it was at Leicester that he first familiarized himself with Malthus' Essay on the Principles of Population and Humboldt's Personal Narrative of Travels in South America. There is, however, evidence that Wallace was probably familiar with at least one of these books some time before his visit to Leicester and that it was during his period in southern Wales that his interest in natural history emerged and developed.