Phillip Sloan has thoroughly documented the importance of Darwin's general invertebrate research program in the period from 1826 to 1836 and demonstrated how it had an impact on his conversion to transformism. Although Darwin later spent eight years of his life investigating barnacles, this period has received less treatment in studies of Darwin and the development of his thought. The most prominent question for the barnacle period that has been attended to is why Darwin "delayed" in publishing his theory of (...) evolution. A related but distinct question concerns the variety of earlier events and influences that led Darwin to the study of "Cirripedia" in 1846, apart from its role in the trajectory that led to "On the Origin of Species ". In this paper I focus on four specific episodes prior to 1846 that inform a picture of why Darwin had an antecedent interest in barnacles: the orientation to collecting strange and curious invertebrate organisms, as well as the strong affinities of Darwin's invertebrate collecting on the Beagle voyage with the work of John Vaughan Thompson; the critical role of marine invertebrate fossils in Darwin's geological reasoning aboard the Beagle and exemplified in his "Geological Observations of South America;" the strange absence of a "Zoology of the Beagle" volume on invertebrates and Darwin's original intent to publish some of the descriptions himself; and the noteworthy presence of barnacles in Darwin's transformation theorizing between 1837 and 1839. There is a wealth of support for the thesis that Darwin had a strong interest in cirripedes prior to the formal barnacle research, blunting arguments that it was psychological aversion or a feeling of inferiority about his taxonomic abilities that drove Darwin to the cirripedes. (shrink)

Butler’s idea of evolution was developed over the publication of four books, several articles and essays between 1863 and 1890. These publications, although never achieving the success expected by Butler, proposed a psychological elaboration of evolution, called ‘unconscious memory’. This was strongly in contrast with the materialistic approach suggested by Darwin’s natural selection. Starting with a historical introduction, this paper aspires to ascertain the logic, meaning and significance of Butler’s idea of ‘unconscious memory’ in the post-Darwinian physiological and psychological Pan-European (...) discussion. Particular attention is devoted to demonstrating that Butler was not only a populariser of science but also an active protagonist in the late Victorian psychological debate. (shrink)