But now, in conclusion, let us briefly consider the great difficulty of the theory that man is descended from some ape-like, arboreal, speechless animal,—the difficulty of bridging over the wide gap which confessedly separates the lowest race of savages from the highest existing race of apes. After all that has been done to diminish the difficulty, it remains a very great one. It is quite true that what is going on at this present time shows how the gap has been widened, and therefore indicates how it may once have been comparatively small. The more savage races of man are gradually disappearing on the one hand, the most man-like apes are being destroyed on the other,—so that on both sides of the great gap a widening process is at work. Ten thousand years hence the least civilized human race will probably be little inferior to the average Caucasian races of the present day, the most civilized being far in advance of the most advanced European races of our time. On the other hand, the gorilla, the chimpanzee, the orang-outang, and the gibbon will probably be extinct or nearly so. True, the men of those days will probably have very exact records of the characteristics not only of the present savage races of man, but of the present races of apes. Nay, they will probably know of intermediate races, long since extinct even now, whose fossil remains geologists hope to discover before long as they have already discovered the remains of an ape as large as man (the _Dryopithecus_) which existed in Europe during the Miocene period;[40] and more recently the remains of a race of monkeys akin to Macacus, which once inhabited Attica. But although our remote descendants will thus possess means which we do not possess of bridging the gap between the highest races of apes and the lowest races of man, the gap will nevertheless be wider in their time. And tracing backwards the process, which, thus traced forward, shows a widened gap, we see that once the gap must have been much narrower than it is. Lower races of man than any now known once existed on the earth, and also races of apes nearer akin to man than any now existing, even if the present races of apes are not the degraded descendants of races which, living under more favourable conditions, were better developed after their kind than the gorilla, chimpanzee, orang, and gibbon of the present time.