"Indeed, if in ascending in the series of animals from the most simply organized animalcule, as from the monad, which seems to be only an animated point, up to the animals the most perfect, or whose structure is the most complicated--in a word, up to animals with mammæ--you observe in the different orders which comprise this great series a gradation, shaded (_nuancé_), although irregular, in the composition of the organization and in the increasing number of faculties, is it not evident that in the case where nature would exert some active power on the existence of these organized bodies she has been able to make them exist only by beginning with the most simple, and that she has been able to form directly among the animals only that which I call the rough sketches or germs (_ébauches_) of animality--that is to say, only these animalcules, almost invisible and to some extent without consistence, that we see develop spontaneously and in an astonishing abundance in certain places and under certain circumstances, while only in contrary circumstances are they totally destroyed? "Do we not therefore perceive that by the action of the laws of organization, which I have just now indicated, and by that of different means of multiplication which are due to them (_qui en dérivent_), nature has in favorable times, places, and climates multiplied her first germs (_ébauches_) of animality, given place to developments of their organizations, rendered gradually greater the duration of those which have originally descended from them, and increased and diversified their organs? Then always preserving the progress acquired by the reproductions of individuals and the succession of generations, and aided by much time and by a slow but constant diversity of circumstances, she has gradually brought about in this respect the state of things which we now observe. "How grand is this consideration, and especially how remote is it from all that is generally thought on this subject! Moreover, the astonishment which its novelty and its singularity may excite in you requires that at first you should suspend your judgment in regard to it. But the observation which establishes it is now on record (_consignée_), and the facts which support it exist and are incessantly renewed; however, as they open a vast field to your studies and to your own researches, it is to you yourselves that I appeal to pronounce on this great subject when you have sufficiently examined and followed all the facts which relate to it.