A highly condensed account of the author's present view of some philosophical problems unresolved in The Structure of Scientific Revolutions. The concept of incommensurability, now considerably developed, remains at center stage, but the evolutionary metaphor, introduced in the final pages of the book, now also plays a principal role.

The species concept is one of the oldest and most fundamental in biology. And yet it is almost universally conceded that no satisfactory definition of what constitutes a species has ever been proposed. The present article is devoted to an attempt to review the status of the problem from a methodological point of view. Since the species is one of the many taxonomic categories, the question of the nature of these categories in general needs to be entered into.

Research in Mendelian heredity was first given permanent institutional support in the U.K. at the John Innes Horticultural Institution. The path by which this was achieved is described. It is shown that Brooke-Hunt in the Board of Agriculture played a decisive part in redirecting the John Innes Bequest from a school for gardeners as intended by the testator to an institute given to research on plants of importance to the horticultural trade. The choice of William Bateson as the institute's first (...) director is traced to the influence of a lobby of academic biologists led by J. B. Farmer. The effects of Bateson's appointment on the shape taken by the new institute and on its subsequent history are described. (shrink)

At the centre of nineteenth-century imperial authority sat the British Museum, which set the standard for discourse about natural history. This paper examines the meaning of those standards, exploring their important but little-understood role in ending the nineteenth-century species debate. The post-Reform Bill political assault on the authority of the British Museum is examined in the light of the ‘species problem’, and a surprising solution by John Edward Gray, keeper of the natural history collection, is seen as both a mediation (...) and a closure of disputes over the meaning of species and the competence of naturalists. Gray's strategic solution – revealed in his copious notes on the parliamentary commissions investigating the affairs of the BM – embodied competence in institutional discourse and set the stage for the supposed ‘cynical’ definition of species later adopted in Darwin's Origin of Species, namely that species are merely what competent naturalists say they are. (shrink)