[8] Thomas, 1888, p, 325.

[9] Förstemann, 1898.

[10] Ibid., 1901, pp. 118-133.

[11] Förstemann, 1901, p. 121.

[12] Ibid., p. 123.

[13] Bowditch, 1910, pp. 211-231.

[14] Ibid., p. 218.

[15] Bowditch, 1910, pp. 222, 223.

[16] Ibid., p. 224.

[17] Ibid., pp. 229, 230.