[4] Lyell, ‘Principles of Geology,’ vol. ii. p. 324. Tenth Edition.
[5] Darwin, ‘Animals and Plants under Domestication,’ vol. ii. p. 251.
[6] 1,073,741,824 grains.
[7] ‘On the Origin of Species,’ p. 74. Fourth Edition.
[8] Darwin, ‘Animals and Plants under Domestication,’ vol. ii. p. 379.
[9] 37 dwts. 7 grs., or 895 grs., between seven and eight times the size of the wild fruit. See ‘Animals and Plants under Domestication,’ vol. i. p. 356.
[10] Darwin, ‘Animals and Plants under Domestication,’ passim.
[11] ‘Animals and Plants under Domestication,’ vol. ii. pp. 348–351.
[12] An important caution may here be quoted from Mr. Herbert Spencer. ‘An impression,’ he says, ‘has been given by those who have popularized the sentiments of Embryologists, that, during its development, each higher organism passes through stages in which it resembles the adult forms of lower organisms—that the embryo of a man is at one time like a fish, and at another time like a reptile. This is not the fact. The fact established is, that up to a certain point the embryos of a man and a fish continue similar, and that then differences begin to appear and increase—the one embryo approaching more and more towards the form of a fish; the other diverging from it more and more. And so with the resemblances to the more advanced types.’—Principles of Biology, vol. i. p. 143.
[13] ‘Origin of Species,’ p. 270. Mr. Darwin shows how the hexagonal cells of the hive-bee can have arisen from the simple cylindrical form, by bringing the cylinders sufficiently near together, so that their outlines, if completed, would intersect.