Well, I have never in my life spent so long looking at genitalia. Let me clarify that: I’m talking about butterfly genitalia, as viewed through the microscope, drawn in large numbers by the considerable lepidopterist Vladimir Nabokov and reproduced (mostly for the first time) in this magnificent book. Some 148 of Nabokov’s scientific drawings appear here, in black and white and in colour, and they form the central section and the chief glory of Fine Lines. They are drawn with exquisite precision, and many of them are strangely beautiful, seeming as much works of art as of scientific enquiry.

Nabokov’s passion for butterflies and love of collecting were lifelong and are well documented, both in his own writings (especially Speak, Memory and the posthumous ‘Father’s Butterflies’, an addendum to The Gift) and in recent studies such as Brian Boyd and Robert Michael Pyle’s Nabokov’s Butterflies. His serious professional work as a lepidopterist peaked in the late 1940s, when he was de facto curator of Harvard’s Museum of Comparative Zoology. That period, during which he nearly ruined his eyesight peering into microscopes, is the focus of Fine Lines. It was a time when there was much controversy over the vexed question of how to define a species. The biological world was divided into ‘splitters’ and ‘lumpers’, basically those who looked for differences between species and those who looked for similarities.

‘The “lumper”’, wrote the American lepidopterist W J Holland, ‘is the horror of the “splitter”, the “splitter” is anathema to the “lumper”; both are the source of genuine grief and much hardship to conscientious men, who are