Materials for the Study of Variation, 1894, p. 30.
Arch. de Zool. Exp. (2) x. 1892, pp. 345-498. On the general subject of adhesion of species, see Bowerbank, Brit. Ass. Rep. 1857, p. 11, who quotes Grant as the first to observe the phenomenon.
Quart. Journ. Micr. Sci. xxii. 1882, p. 229.
But see Gamble and Keeble, Quart. Journ. Micr. Sci. xlvii. 1904, p. 363, who show that various green animals really owe their colour to "algae," though the infection with the "alga" is difficult to detect because it takes place by means of a colourless cell. See also Zoochlorella, on p. [126].
Sollas, Tr. Dublin Soc. (2) iii. 1884, p. 87.