effect of education and habit on the cerebral elements. This state lasted some weeks, and the "recollection" of what had been "forgotten," to use conventional terms, was slow and painful, needing, or, as I would now say, seeming to require, a process of reëducation as distinct as (though, I judge, less prolonged than) that which proved necessary in the case detailed by Professor Sharpey. In the end recovery was mentally and physically satisfactory.
I can not assume that anything in these two narratives will strike the practical psychologist as novel, or of even unfrequent occurrence. The clinical aspect of such cases has been sketched times without number. Nevertheless they present features of interest, as viewed from an etiological standpoint, which may be worthy more than a passing notice.
Either of three conditions may, I believe, be set up by brain disturbance, or disease, causing "loss of memory": 1. Complete destruction of cerebral cells; 2. Withering or blighting, which amounts to obliteration of the cells without destruction of their nuclei;[1] 3. A suspension of function without arrest of nutrition, as though a particular area of the cerebral organism were thrown out of the circuit of energy.
In the first event there will be final effacement of the records of ideation. So far as the cells destroyed are concerned, they and their properties are lost for ever. If the functions previously performed by these strata or tracts reappear, it must be because some other part of the brain has taken up the business vicariously—as I believe is possible with nearly every function or manifestation of mental energy. In the second event, when the cells are withered but the nuclei remain, a new crop of cells may spring from the parent organism, and, after a lapse of time sufficient for development, the educationary record will reappear, the seed reproducing its kind, plus the effect of training and ideation. It may be that there will need to be so much reeducation as to cultivate the new growth, and perhaps a reimpression of purely objective ideas, but it may, and probably in the majority of instances does, happen that the new cells will be developed with all the characteristics of the old. In the third event recovery may occur instantly, almost at any moment, if the obstacle to communication is overcome or breaks down in convalescence, so that the isolated, but scarcely injured, congeries of brain-cells may again be energized, I speak of brain-cells instead of "nerve-molecules," because, even accepting the vibration theory, it must be assumed that the vibrating particles are cellular vital organisms.
Supposing the states I have described to exist, I venture to suggest that the development of a new crop of cells from denuded germs or nuclei will account for the facility with which reeducation, in cases like that described by Professor Sharpey, reproduces knowledge, even
- ↑ I use the term nucleus here and throughout in a non-physiological sense, simply to designate the seat of life in a cell, whatever that may be.
