Page:The Zoologist, 4th series, vol 1 (1897).djvu/202

174 consider many of our conclusions absolutely unassailable. Thus Dr. Reid remarks:—"A young chick, for instance, emerges from the egg the possessor of a large amount of hereditary knowledge," and alludes to the brilliant researches on that matter by the late Douglas Spalding. With Dr. Reid we had all accepted the result of these researches as final; but now Prof. Lloyd Morgan has repeated the experiments, and shown that many of Mr. Spalding's conclusions are erroneous. It is only just to remark, however, that Dr. Reid had evidently no opportunity of consulting the then unpublished observations of Prof. Lloyd Morgan.

The second section is devoted to "The present evolution of Man." It is scarcely necessary to restate the common consensus of opinion that the evolution of Man, so far as general structure is concerned, has ceased, or, in other words, has arrived at an equilibrium with surrounding conditions. This is indeed so prevalent a conception, that by many of our best and most progressive thinkers the human evolution of the future is considered to lie purely in the domain of ethics. There is still, however, a physical arena where the struggle ensues, in which the survivors are not necessarily the strong in limb and mind alone, but "the strong against disease." To use the words of our author: "The present evolution of Man is therefore not mainly an evolution of physical or intellectual strength, as in his remote ancestry, but mainly an evolution against disease, and wherever men are crowded together, and can take disease from one another, or there are other unfavourable circumstances, especially against zymotic disease—that is, disease due to or produced by living micro-organisms."

Such diseases are not confined to Man alone, but are found to ravage other animals, and instances of such devastation will recur to the minds of most zoologists. In calling attention to this important factor, with the authority of personal experience and many gathered facts, Dr. Reid has undoubtedly introduced us to one of the neglected and by no means insignificant byways which intersect the broad road of evolution.