"In the face of all these facts, it may be easily understood that anthropologists, however little in harmony they may sometimes be on other points, are agreed on this, and have equally been led to the conclusion that there is nothing that permits us to look at the brain of the ape as the brain of man smitten with an arrest of development, or, on the other hand, the brain of man as a development of that of the ape (Gratiolet); that the study of animal organism in general, and that of the extremities in particular, reveals, in addition to a general plan, certain differences in shape and arrangement which specify two altogether special and distinct adaptations, and are incompatible with the idea of any filiation (Gratiolet and Alix); that in their course of improvement and development, apes do not tend to become allied to man, and conversely the human type, when in a course of degradation, does not tend to become allied to the ape (Bert); finally, that no possible point of transition can exist between man and the ape, unless under the condition of inverting the laws of development (Pruner-Bey), &c. "What, we may ask, is brought forward by the partisans of the simial origin of man in opposition to these general facts, which here I must confine myself to merely pointing out, and to the multitude of details of which these are only the abstract? "I have done my best to seek out the proofs alleged, but I everywhere meet with nothing but the same kind of argument--exaggerations of morphological similarities which no one denies; inferences drawn from a few exceptional facts which are then generalised upon, or from a few coincidences in which the relations of cause and effect are a matter of supposition; lastly, an appeal to _possibilities_ from which conclusions of a more or less affirmative character are drawn. "We will quote a few instances of this mode of reasoning. "1st. The bony portion of the hand of man and of that of certain anthropomorphous apes present marked similarities. Would it not therefore have been possible for an almost imperceptible modification to have ultimately led to identity? "MM. Gratiolet and Alix reply to this in the negative; for the muscular system of the thumb establishes a profound difference, and testifies to an _adaptation_ to very different uses. "2nd. It is only in man and the anthropomorphous apes that the articulation of the shoulder is so arranged as to allow of rotatory movements. Have we not here an unmistakable resemblance? "The above-named anatomists again reply in the negative; for even if we only take the bones into account, we at once see that the movements could not be the same; but when we come to the muscular system, we find decisive differences again testifying to certain special _adaptations_.