Ewart was born in
Penicuik,
Midlothian, Scotland, the son of Jean Cossar and John Ewart, a joiner. He studied medicine from 1871 to 1874 at the
University of Edinburgh where he graduated with an MB ChB. After graduation, he became an anatomy demonstrator under
William Turner and then held the position of Curator of the Zoological Museum at
University College, London, where he assisted
Ray Lankester (later director of the Natural History Museum) by making zoological preparations for the museum and providing teaching support for Lankester's course in practical zoology. In Aberdeen he encountered
James Duncan Matthews, a mature student (older than himself) and they became friends until Matthew's premature death in 1890. In 1879 he was elected a Fellow of the
Royal Society of Edinburgh. His proposers were
Sir William Turner, William Rutherford,
William Rutherford Sanders and
John Chiene. He won the Society's Neill Prize for 1895-98 and served as their Vice-President 1907 to 1912. He was elected a
Fellow of the Royal Society in June 1893, having jointly delivered their
Croonian Lecture in 1881. Among various other studies, he performed breeding experiments with
horses and
zebras. He carried out these experiments at "The Bungalow", now the Navaar House in Penicuik, well before the rediscovery of
Gregor Mendel's works. Ewart crossed a male zebra with a female
pony to show that the theory of
telegony inherited from the Greeks was unsound. Telegony held that a female with a history of mating with multiple males would pass on genetic qualities of all previous partners to her offspring. Ewart later bred the mare which had produced zebra-horse hybrids with a pony, and the offspring showed no zebra qualities in either markings or temperament. Ewart's goal was also to produce a draught animal for South African conditions, resistant to African diseases and more tractable than a mule. In 1883 he commissioned
George Washington Browne to design a grand new house in Penicuik, finished in 1885, which is where he died on New Year's Eve 1933/34. It is now the Craigiebield House Hotel. ==Family==