[15]. Sachs, p. 83.
[16]. Ibid. p. 147.
[17]. A Treatise on Comparative Embryology. By Francis M. Balfour, LL.D., F.R.S. Vol. ii, p. 343 (second edition).
[18]. Balfour, l.c. Vol. ii, 400-1.
[19]. Balfour, l.c. Vol. ii, p. 401.
[20]. For a general delineation of the changes by which the development is effected, see Balfour, l.c. Vol. ii, pp. 401-4.
[21]. See Balfour, Vol. i, 149 and Vol. ii, 313-4.
Note.
After the above articles were published, I received from Dr. Downes a copy of a paper “On the Influence of Light on Protoplasm,” written by himself and Mr. T. P. Blunt, M.A., which was communicated to the Royal Society in 1878. It was a continuation of a preceding paper which, referring chiefly to Bacteria, contended that—
“Light is inimical to, and under favourable conditions may wholly prevent, the development of these organisms.”