"1. That all the organized bodies of our globe are true productions of Nature, which she has successively formed after the lapse of much time; "2. That, in her course. Nature has begun, and begins over again every day, to form the simplest organisms, and that she directly creates only those, namely, which are the first germs (_ébauches_) of organization, which are designated by the expression of _spontaneous generations_; "3. That the first germs of the animal and plant having been formed in appropriate places and circumstances, the faculties of a beginning life and of an organic movement established, have necessarily gradually developed the organs, and that with time they have diversified them, as also the parts; "4. That the power of growth in each part of the organized body being inherent in the first created forms of life, it has given rise to different modes of multiplication and of regeneration of individuals; and that consequently the progress acquired in the composition of the organization and in the shape and diversity of the parts has been preserved; "5. That with the aid of sufficient time, of circumstances which have been necessarily favorable, of changes of condition that every part of the earth's surface has successively undergone--in a word, by the power which new situations and new habits have of modifying the organs of living beings, all those which now exist have been gradually formed such as we now see them; "6. Finally, that, according to a similar order of things, living beings having undergone each of the more or less great changes in the condition of their structure and parts, that which we call a _species_ among them has been gradually and successively so formed, having only a relative constancy in its condition, and not being as old as Nature herself. "But, it will be said, when it is supposed that by the aid of much time and of an infinite variation in circumstances, Nature has gradually formed the different animals known to us, shall we not be stopped in this supposition by the simple consideration of the admirable diversity which we observe in the _instincts_ of different animals, and by that of the marvels of every kind presented by their different kinds of _industry_?