Memory in the Germ-plasm

Abstract

IF “a lamb's tail is shortened” and the germ-cell “records” the event, surely there is more to be “remembered” by it than a “momentary cut”, viz. a permanent change of shape? Setting aside mutilations, there remain use-acquirements. From infancy forwards a man develops physically and mentally, principally under the stimulus of use. For instance, the muscles of an infant's limbs do not grow unless used. His mind is almost blank at birth, but grows under the influence of experience (use). In this way he learns to coordinate his muscles and a vast deal more. Prolonged parental protection affords the opportunity. In proportion as animals are low in the, scale of life they appear to be less and less capable of making use-acquirements until they are quite incapable. Most insects, for example, are not protected by their parents, and must come into the world fully equipped physically and mentally to cope with the environment. They have no need for use-acquirements, and apparently make none. It seems clear, then, that the power of developing under the stimulus of use (plasticity, as it is called) is a product of evolution. It confers the immensely valuable trait of adaptability on the individual. The position, then, appears to be this: low animals cannot make, use-acquirements, and therefore can transmit none; higher animals can make use-acquirements, but obviously transmit none, for in them the innate has been progressively replaced by the acquired. When we speak of the transmission of a use-acquirement, we do not really mean that the child has inherited the parental trait—we mean that the trait has been transmuted into something very different and much less useful, an innate character. In other words, we suppose that the adaptability of the parent is replaced by rigidity in the child, and we suppose this in spite of enormous and conclusive evidence to the contrary. We close our eyes carefully to facts, and found our science on vague analogies.