The molecular structure of vegetables and animals has been investigated by men of science in their minutest details; the fragment of a tooth, bone, or shell, recent or fossil, is sufficient to determine the nature of the animal to which it belonged; and, if fossil, to assign the geological period at which it had lived, whether on the earth, in the waters, or the air. By the microscopic examination of a minute Foraminifer or shell-like organism, it has been proved beyond a doubt that the Eozoön, an animal which existed at a geological period whose remoteness in time carries us far beyond the reach of imagination, only differs in size from a kind living in the present seas. Simplicity of structure has preserved the race through all the geological changes which, during millions of centuries, have swept from existence myriads of more highly organized beings. The Eozoön is the most ancient form of life known, and was probably an inhabitant of the primeval ocean. Patches of carbonaceous matter imbedded in the same strata show that vegetation had already begun; so at that most remote period of the earth’s existence, the vivifying influence of the sun, the constitution and motions of the atmosphere and ocean, and the vicissitudes of day and night, of life and death, were the same as at the present time. Footnotes Footnote 1: The nervous system is ably explained in Dr. Carpenter’s ‘Manual of Physiology.’ Footnote 2: A pointer and greyhound, belonging to a friend of the author’s, repeatedly brought home hares. Upon watching the dogs, the pointer was seen to find the hare, which was coursed and killed by the greyhound. Singular as this may seem, it is by no means unprecedented. Footnote 3: From _rhizon_, a root, and _pous_, _podos_, a foot. Footnote 4: ‘On the Amœba princeps and its reproductive cells,’ by Mr J. H. Carter: _Annals of Natural History_, July 1863. Footnote 5: ‘On Difflugian Rhizopods,’ by G. C. Wallich M.D. _Annals of Natural History_, March, 1864. Footnote 6: Dr. Wallich. Footnote 7: ‘Introduction to the Study of the Foraminifera,’ by W. B. Carpenter. Footnote 8: A complete description of this complex type is given by Dr. Carpenter in the Phil. Trans. 1856. Footnote 9: Dr. Carpenter. Footnote 10: Structure of the Organic Remains in the Laurentian Rocks of Canada: by J. W. Dawson. Esq., Principal of M‘Gill University, Montreal. Footnote 11: The discovery of Eozoön and the minute details of its structure are published in the _Intellectual Observer_ for May 1865. Also the ‘Laurentian Rocks of Canada,’ a small work, contains articles by various authors on the occurrence, structure, and mineralogy of certain organic remains of these rocks. Footnote 12: ‘Histoire Naturelle des Animaux sans Vertèbres,’ par MM. Deshayes et H. Milne-Edwards. Footnote 13: Memoir by Dr. Bowerbank in the Transactions of the Microscopic Society.