Here the late Professor Roy's article on "Flight" (A. Newton, Dict. Birds, 1893, p. 260) may be consulted.
Ogilvie Grant, Ibis, 1896, p. 52.
Id. ibid.
Ibis, 1865, pp. 281, 282.
Harvie-Brown, Zoologist, 1894, p. 337-338.
Here the late Professor Roy's article on "Flight" (A. Newton, Dict. Birds, 1893, p. 260) may be consulted.
Ogilvie Grant, Ibis, 1896, p. 52.
Id. ibid.
Ibis, 1865, pp. 281, 282.
Harvie-Brown, Zoologist, 1894, p. 337-338.