(1) BIGGART, To be published. (2) WEIDENREICH, Quoted by Jolly. (3) BADERTSCHER, 1913, Am. Journ. Anat., Vol. 15, p. 69. (4) BARBANO, 1914, Virch. Arch., Vol. 217, p. 3. (5) BROWN, 1898, Journ. Exp. Med., Vol. 3, p. 315. (6) RINGOEN, 1915, Anat. Record, Vol. 9, p. 683. (7) DOWNEY, 1915, Folia Haemat., Vol. 19, p. 148. (8) Rous, 1908, Journ. Exp. Med., Vol. 10, p. 537. (9) HABERSHON, 1906, Journ...