“…Of cases in which, with or without a cyst, aggregations of pigmented tissue have been observed microscopically I can find only 14 inf the relevant literature: 10 human-Haab (1.881),-Zimmermann (1893), van Duyse (1899), Bietti (1901), Hanke (1904), Cecchetto (1920), Triepel (1921), Gallemearts (1924), Recordon and, Griffiths (1938), Whitnall and Norman (1940); and 4 in animals-de Bary (1887) and Albrecht (1.895) in the calf, 'Collins and Parsons (1903) in the chick,' and the Chases (1941) in mice. Some similar cases are cited by other authors 'also, but from clinical examination only.…”