Page:Popular Science Monthly Volume 25.djvu/189

Rh, owing to lesion of the internal capsule, there are, according to the gravity of the lesion, three degrees or depths (of course the division into three degrees is arbitrary). In the first degree there is some paralysis of the face, arm, and leg; in the second degree there is more paralysis of these parts, and, in addition, there is a greater range of paralysis; the patient's head and eyes are turned from the side paralyzed. Here is illustrated what I call "compound order." The difference between the two degrees is not that in the second there is more paralysis only, nor that there is a greater range of paralysis only, but in both respects; there is more paralysis of the parts affected in the first degree and extension of range of paralysis to parts beyond them. An adequate doctrine of localization has to account for such increase of paralysis in compound order on increasing gravity of lesions. In the third degree of, or rather beyond, hemiplegia there is universal immobility. In this degree the patient has lost consciousness, and this loss may be said to explain why he does not move the other or "second" side of his body. I hope to show later that explanations of materialistic states by psychical states are invalid. I wish here to bring evidence in support of the opinion I have long held, that all parts of both sides of the body are represented in each half of the brain. The view I take is simply an extension of Broadbent's hypothesis, already referred to. My supposition is that the limbs of the two sides are very unequally represented in each half of the brain, while the bilaterally acting muscles are very nearly equally represented in each half. Evidence that at least some parts of both sides of the body are represented in each half of the brain is that consecutive to a negative lesion of one internal capsule there is wasting of nerve-fibers "descending" into both sides of the spinal cord.

Degrees of epileptiform seizures illustrate different depths of dissolution. There are degrees of these from (to take an example) spasm of the thumb and index-finger to universal convulsion. That these degrees are compound is very evident. The first stage of the fit is, to speak roughly, that the arm is a little affected; the second stage is that the arm is more affected, and the face a little; the third stage is that the arm is most affected, the face much, and the leg a little. This compound order of spreading, which any adequate doctrine of localization has to account for, may be symbolized thus: a, then a$2$+f, then a$3$+f$2$=l etc. There are degrees beyond this to universal spasm; these cases I submit supply further evidence that both sides of the body are represented in each half of the brain. Certain experiments of Franck and Pitres bear in a most important way on the question