That this end is secured without the aid of consciousness in the case of many organic species, in all those, for example, which we classify as plants, must not be taken as presumptive evidence that in other species, for instance in the multitudinous host of insects, the development of conscious situations is of no biological value. The fact that chlorophyll is not developed in any mammal does not show that the possession of this substance is of no service to the higher plants. It would not be worth while to give expression to this very obvious truth, were it not that critics of natural selection persistently argue that because one species gets on perfectly well without this or that particular character it can have played no part in securing the survival of another species. When I described, at a meeting of naturalists, how well young chicks could swim, such a critic drew me aside after the meeting, and expressed his surprise that this did not convince me that the webbed foot of the duck could not logically be attributed to natural selection. This is an extreme case, and one obviously taken on peculiarly weak grounds. But even Huxley urged that, because a frog, from which the cerebral hemispheres have been removed, performs many co-ordinated actions without conscious guidance, consciousness is, throughout nature, merely an accompaniment of certain molecular changes in the brain. “Such a frog,” he says,[197] “walks, hops, swims, and goes through his gymnastic performances quite as well without consciousness, and consequently without volition, as with it; and if a frog, in his natural state, possesses anything corresponding with what we call volition, there is no reason to think that it is anything but a concomitant of the molecular changes in the brain which form part of the series involved in the production of motion. “The consciousness of brutes,” he continues, “would appear to be related to the mechanism of their body simply as a collateral product of its working, and to be as completely without any power of modifying that working as the steam-whistle which accompanies the work of a locomotive engine is without influence on its machinery. Their volition, if they have any, is an emotion indicative of physical changes, not a cause of such changes. It does not enter into the chain of causation of their actions at all.” If the literal truth of this contention--the logical soundness of this conclusion--be admitted, it seems absurd to speak of the biological value of consciousness in behaviour or to discuss the importance of the _rôle_ that is played by the development of conscious situations in securing the biological end of racial preservation.