In 1863, M. Desnoyers found in the upper strata of the tertiary beds (pliocene) at Saint-Prest, in the department of Eure, certain bones belonging to various extinct animal species; among others those of an elephant (_Elephas meridionalis_), an animal which did not form a part of the quaternary _fauna_. On most of these bones he ascertained the existence of cuts, or notches, which, in his opinion, must have been produced by flint implements. These indications, according to M. Desnoyers, are signs of the existence of man in the tertiary epoch. This opinion, however, Sir Charles Lyell hesitates to accept. Moreover, we could hardly depend upon an accident so insignificant as that of a few cuts or notches made upon a bone, in order to establish a fact so important as that of the high antiquity of man. We must also state that it is a matter of question whether the beds which contained these notched bones really belong to the tertiary group. The beds which correspond to the quaternary epoch are, therefore, those in which we find unexceptionable evidence of the existence of man. Consequently, in the quaternary epoch which preceded the existing geological period, we must place the date of the first appearance of mankind upon the earth. If the purpose is entertained of discussing, with any degree of certainty, the history of the earliest days of the human race--a subject which as yet is a difficult one--it is requisite that the long interval should be divided into a certain number of periods. The science of primitive man is one so recently entered upon, that those authors who have written upon the point can hardly be said to have properly discussed and agreed upon a rational scheme of classification. We shall, in this work, adopt the classification proposed by M. Édouard Lartet, which, too, has been adopted in that portion of the museum of Saint-Germain which is devoted to pre-historic antiquities. Following this course, we shall divide the history of primitive mankind into two great periods: 1st. The Stone Age; 2nd. The Metal Age. These two principal periods must also be subdivided in the following mode. The "Stone Age" will embrace three epochs: 1st. The epoch of extinct animals (or of the great cave-bear and the mammoth). 2nd. The epoch of migrated existing animals (or the reindeer epoch). 3rd. The epoch of domesticated existing animals (or the polished-stone epoch). The "Metal Age" may also be divided into two periods: 1st. The Bronze Epoch; 2nd. The Iron Epoch. The following synoptical table will perhaps bring more clearly before the eyes of our readers this mode of classification, which has, at least, the merit of enabling us to make a clear and simple statement of the very incongruous facts which make up the history of primitive man: