Remarkably enough, at almost the same period[274] Professor Huxley concluded a discussion of palæontological evidence with a precisely contrary pronouncement--"The whole evidence is in favour of Evolution, and there is none against it." On other occasions, also, he distinctly maintained that it is just this line of enquiry which conclusively establishes Evolution as no longer a theory, but an historical fact. To such a conclusion, he tells us,[275] "an acute and critical-minded investigator is led by the facts of palæontology;"--and, again, "If the doctrine of Evolution had not existed, palæontologists must have invented it, so irresistibly is it forced upon the mind by the study of the remains of the Tertiary mammalia." Such declarations clearly challenge consideration, especially when it is remembered how strict were the views which Professor Huxley professed as to the necessity of proofs for our beliefs,--"that it is wrong for a man to say he is certain of the objective truth of any proposition unless he can produce evidence which logically justifies that certainty."[276] We therefore turn naturally to his lectures on Evolution, wherein he treats the palæontological argument _ex professo_, and we find that his verdict is based upon a few selected instances, such as that of the reptilian birds already mentioned, which he considers favourable to Evolution, and one which he terms _demonstrative_,--namely that of the Horse. This he treats in some detail; in regard of it he delivers the positive judgment which we have just heard, and it therefore in a special manner demands our attention. As furnishing evidence for the history of the horse, two features are of special importance, his limbs, and his teeth. Of these we may confine our attention to the former, as being, at once, sufficient for our purpose, and within the scope of ordinary observation. The horse family, or _Equidae_, belong to the tribe of Ungulates, or hoofed animals, some points of whose anatomy require to be considered in relation to our own. Taking first the fore-limbs. What we call the "knee" of a horse is in reality the wrist,--the true knee, or rather elbow, being what we call the "shoulder." Below the knee comes the "cannon bone," corresponding to the middle bone of the hand, and below it the "pastern," "coronary," and "coffin" bones, representing the joints of the solitary middle-finger, while the hoof is its greatly enlarged and thickened nail. Similarly, in the hind-limbs; the "hock" is veritably the ankle, and again the lateral digits are suppressed, the middle toe alone remaining.