dissections, mostly of cardiac muscle , the urinary bladder and the prostate. He held the position for five years. During this time he started to collect evidence that led to his pioneering theories of flight. In 1867 he gave lectures to the Linnean Society on the nature of the mechanical appliances necessary to make flight possible. He showed that the figure-of-8 movements of wings in the animal kingdom were identical to those made by wings in flight. In 1867 he became unwell suffering from 'a condition of the retina'. He took a break in Ireland to continue to study the flight of birds and bats. In 1870 he published his theory of flight in which he demonstrated that: insects, bats, and birds fly by figure-of-eight movements; that the wing of the insect, bat and bird, are screws structurally like the blade of a screw propeller; that wings have a reciprocating action and that wings describe a figure-of-eight track. He had a passionate interest in animal locomotion and, more particularly, in the theory of flight, and around the turn of the century made several prototypes of an ornithopter of his own design. In 1868, at the age of 36, Pettigrew was elected a Fellow of the Royal Society. In 1869 he returned to Scotland to take up an honorary position as Curator of the museum of the Royal College of Surgeons of Edinburgh and employment as pathologist to the Edinburgh Royal Infirmary. In 1873 he was elected a Fellow of the Royal Society of Edinburgh his proposer being Sir Thomas Richard Fraser and later that year was elected a Fellow of the Royal College of Physicians of Edinburgh. In March 1873 he became a lecturer in Physiology at the Edinburgh Extramural School of Medicine. In 1873, Pettigrew published Animal Locomotion: or Walking, Swimming and Flying, his most popular work. In 1875, he was appointed to the Chandos Chair of Medicine and Anatomy at St Andrews University and established a home on The Scores which he called Swallowgate because of its situation which allowed him to observe birds in flight. Over several subsequent years, Pettigrew assembled his magnum opus Design in Nature, published in three volumes and lavishly illustrated with engravings and photographs. Its publication was completed in 1908. In this work, he showed some indifference to Darwinism and mainstream evolutionary biology, favouring teleological points of view instead. His reputation was subsequently