Ib. Vol. i, p. 241.
47
Kent, Vol. i, p. 56.
48
Ib. Vol. i, p. 57.
49
The Elements of Comparative Anatomy, by T. H. Huxley, pp. 7-9.
50
A Treatise on Comparative Embryology, by F. M. Balfour, Vol. ii, chap. xiii.
51
Sachs, p. 210.
52
Ibid. pp. 83-4.
53
Ibid. p. 185.
54
Ibid. 80.
55
Sachs, p. 83.
56
Ibid. p. 147.
57
A Treatise on Comparative Embryology. By Francis M. Balfour, LL.D., F.R.S. Vol. ii, p. 343 (second edition).
58
Balfour, l.c. Vol. ii, 400-1.
59
Balfour, l.c. Vol. ii, p. 401.
60
For a general delineation of the changes by which the development is effected, see Balfour, l.c. Vol. ii, pp. 401-4.
61
See Balfour, Vol. i, 149 and Vol. ii, 343-4.