Workers in the finer structure of the nervous system are suffering from a plethora of observations. New and more searching methods are being discovered every day, and no sooner does he who sets about constructing a scheme of the central nervous system arrive at something which appears to be satisfactory than he has to pull it to pieces and reconstruct it, to fit in further detail which has been brought to light in the meanwhile. Until this vast array of observations has been properly digested, a process which may well take years, we can scarcely hope to obtain a scheme of the relationship of the nerve-cells to one another which will be more than a working hypothesis.