It is of philosophical and epistemological interest to examine how Darwin conceived the process of division of labour within Natural History. Darwin observed the advantages brought by division of labour to the human economy, and considered that the principle of divergence within nature, which is, according to him, one of the two ‘keystones’ of his theory, gave comparable advantages. This led him to re-examine Milne-Edwards’ view on the notion of division of physiological labour, and to introduce this with modifications into (...) his naturalist writings. After a short review of the Darwinian historiography dealing with this issue, I first show the conceptual confusion into which Darwin plunges, when using a so-called economic argument to defend his thesis of the maximization of beings in a given territory due to division of labour. Following this I propose several hypotheses to explain these shifts, recurring in Darwin’s texts, from one conception and from one application to another, of the division of labour. (shrink)