[Footnote: _Beneath the shoreless waves_, l. 295. The earth was originally covered with water, as appears from some of its highest mountains, consisting of shells cemented together by a solution of part of them, as the limestone rocks of the Alps; Ferber's Travels. It must be therefore concluded, that animal life began beneath the sea. Nor is this unanalogous to what still occurs, as all quadrupeds and mankind in their embryon state are aquatic animals; and thus may be said to resemble gnats and frogs. The fetus in the uterus has an organ called the placenta, the fine extremities of the vessels of which permeate the arteries of the uterus, and the blood of the fetus becomes thus oxygenated from the passing stream of the maternal arterial blood; exactly as is done by the gills of fish from the stream of water, which they occasion to pass through them. But the chicken in the egg possesses a kind of aerial respiration, since the extremities of its placental vessels terminate on a membranous bag, which contains air, at the broad end of the egg; and in this the chick in the egg differs from the fetus in the womb, as there is in the egg no circulating maternal blood for the insertion of the extremities of its respiratory vessels, and in this also I suspect that the eggs of birds differ from the spawn of fish; which latter is immersed in water, and which has probably the extremities of its respiratory organ inserted into the soft membrane which covers it, and is in contact with the water.] [Footnote: _First forms minute_, l. 297. See Additional Note I. on Spontaneous Vitality.] "Thus the tall Oak, the giant of the wood, Which bears Britannia's thunders on the flood; The Whale, unmeasured monster of the main, The lordly Lion, monarch of the plain, The Eagle soaring in the realms of air, Whose eye undazzled drinks the solar glare, Imperious man, who rules the bestial crowd, Of language, reason, and reflection proud, 310 With brow erect who scorns this earthy sod, And styles himself the image of his God; Arose from rudiments of form and sense, An embryon point, or microscopic ens! "Now in vast shoals beneath the brineless tide, On earth's firm crust testaceous tribes reside; Age after age expands the peopled plain, The tenants perish, but their cells remain; Whence coral walls and sparry hills ascend From pole to pole, and round the line extend. 320 [Footnote: _An embryon point_, l. 314. The arguments showing that all vegetables and animals arose from such a small beginning, as a living point or living fibre, are detailed in Zoonomia, Sect. XXXIX. 4. 8. on Generation.]