The development of the motor and sensory areas of the brain are in a measure dependent on each other, and that great region in front, which probably functions in all the higher mental processes, must evidently be hindered in its growth and development if the region back of it is defective. It is impossible to have thought without the material for thought; and this can, so far as all perceptions of matter are concerned, be derived chiefly, if not wholly, through the sensory and motor areas working together. This furnishes a physiological basis for the discussion of manual training and all kindred subjects.
These views have received recent confirmation by an examination of the brain of the late celebrated Laura Bridgman, who was defective in all the senses except the tactile and the muscular sense, while absolutely wanting in vision and hearing. Her brain was found much smaller in the sensory areas and its nervous cells few and undersized, owing to disuse, leading to atrophy and failure of development. Experience proves conclusively that all those mental processes on which reflection and judgment depend are in their natural order later of development. Now it is, in my opinion, of great moment to observe in education the natural sequence of development, as any attempt to reverse Nature's order is sure to result in serious harm. We can not bring about in a boy of sixteen a development which should have been begun at five; and this lies at the very root of the question of science in schools, and all others bearing on education. Some have been wondering what all this has to do with science in schools; but I hope to show before I conclude that, according to the homely adage, the longest way around is sometimes the shortest way home.
If my conclusions have thus far been sound, we should be a long way on the road to solving the most important part of any educational problem, viz., the nature of the human brain and mind. The other part of the problem, how best to adapt to the environment, or fit the environment to the mind, is subordinate, though sometimes practically difficult.
It is plain that we must cultivate the senses, and that at the period when they are most susceptible of it, in early youth; that to do this we must not neglect the use of the muscles, or more correctly neuro-muscular activities, for muscular movement of course implies the co-operation of the central nervous system, including the sensory brain areas.
The highest aim of science is to reach great general laws like that which marks the triumph of the science of the nineteenth century, the most important of which is the law of the conservation of energy. But, before any law can be established, a vast number of facts must be gathered. Facts, as regards natural science, mean