met in 1903, when a subspecies of Xanthopan morganii was found in Madagascar with a proboscis about 12 inches (300 mm) long, and was named Xanthopan morganii praedicta to celebrate this verification of a testable prediction made by Darwin on the basis of his theory of natural selection. Influence Michael Ghiselin has expressed the view that all studies of coevolution follow directly or indirectly from Darwin's orchid book, which was also the origin of all work on the evolution of extreme specialisation. Its publication led almost immediately to research by many other naturalists into specialisation and coevolution, in some cases analysing other taxa. In his autobiography, Darwin modestly recalled how this work had revived interest in Christian Konrad Sprengel's neglected ideas: Among the many prominent biologists who began research on coevolution, Hermann Müller was particularly interested in the evolutionary sequence in which insects and flowers became adapted to each other. Like Darwin, he began with the premise that flowers were adapted to ensure cross-fertilisation, and added his own premise that most insects were not "limited by hereditary instinct to particular flowers". On this basis, he developed the view that specialisation develops from the need for flowers to attract pollinating insects (without making access too easy for non-pollinators), and from the evolution of pollinators to adapt to changes in the location of rewards such as nectar. He found that alpine flowers tended to be visited by bees at lower altitudes, and by butterflies at higher altitudes, beginning research on the idea that plants at different altitudes were specialised for different pollinators. By comparing related plant species that he thought had diverged in form from a common ancestor, and testing whether they were visited by butterflies or bees, he was the first to use a combination of morphological and ecological approaches to understand patterns in the evolution of interactions and specialisation. His brother Fritz Müller used similar methods when studying mimicry in Brazil. The early development of ideas on specialisation and coevolution became increasingly focused on the problem of mimicry; Henry Walter Bates had initially raised this issue in a paper read to the Linnean Society of London in December 1861 in Darwin's presence, and published in November 1862. Others basing their studies of reproductive ecology on Darwin's evolutionary approach included Friedrich Hildebrand and Severin Axell in Europe, Asa Gray and Charles Robertson in North America. In Italy, Federigo Delpino adopted the