I will not, at present, particularly insist upon this idea. I dislike the mere appearance of impugning even simple interpretations if they have the sanction of the church, and wish merely to intimate that their authority might, perhaps, be questioned without transgressing the limits established by the church.[139] If this is not the case, and we must accept, in the main, the opinions of the believers in unity, I still do not despair that the facts may be explained in a manner different from theirs, and that the principal physical and moral differences among the branches of the human family may exist, with all their necessary consequences, independently of unity or plurality of origin. The specific identity of all canines is acknowledged,[140] but who would undertake the difficult task of proving that all these animals, to whatever variety they may belong, were possessed of the same shapes, instincts, habits, qualities? The same is the case with many other species, the equine, bovine, ursine, etc. Here we find perfect identity of origin, and yet diversity in every other respect, and a diversity so radical, that even intermixture can not produce a real identity of character in the several types. On the contrary, so long as each type remains pure, their distinctive features are permanent, and reproduced, without any sensible deviation, in each successive generation.[141] This incontestable fact has led to the inquiry whether in those species which, by domestication, have lost their original habits, and contracted others, the forms and instincts of the primitive stock were still discernible. I think this highly improbable, and can hardly believe that we shall ever be able to determine the shape and characteristics of the prototype of each species, and how much or how little it is approached by the deviations now before our eyes. A very great number of vegetables present the same problem, and with regard to man, whose origin it is most interesting and important for us to know, the inquiry seems to be attended with the greatest and most insurmountable difficulties. Each race is convinced that its progenitor had precisely the characteristics which now distinguish it. This is the only point upon which their traditions perfectly agree. The white races represent to themselves an Adam and Eve, whom Blumenbach would at once have pronounced Caucasians; the Mohammedan negroes, on the contrary, believe the first pair to have been black; these being created in God's own image, it follows that the Supreme Being, and also the angels, are of the same color, and the prophet himself was certainly too greatly favored by his Sender to display a pale skin to his disciples.[142]