[13] Address to the British Association1902, Section Physiology.

[14] This enumeration of the elements that enter into the structure of plants and animals is taken from Professor F.J. Allen's paper already referred to.

[15] Early History of Mankind 2nd ed. p. 227.

[16] For a fuller account of this Arctic fauna and flora see the works of Sir C. Lyell, Sir A. Geikie, and other geologists. A full summary of it is also given in the author's Island Life.

[17] Professor G.H. Darwin states that it is nearly certain that no other satellite nor any of the planets originated in the same way as the moon.

[18] Transactions of Royal Dublin Society, vol. vi. (ser. ii.), part xiii. 'Of Atmospheres upon Planets and Satellites.' By G. Johnstone Stoney, F.R.S., etc. etc.

[19] Knowledge, June 1903.

[20] M. Camille Flammarion, in Knowledge, June 1903.

[21] The Worlds of Space, by J.E. Gore, chapter iii.

[22] The Fortnightly Review, April 1903, p. 60.