great importance is Wegener's communication, in which he states that, in cases of neuritis, muscle tissue is decomposed.
Finally, we may refer to the fact that experiments have been made with a view to throwing light upon the etiology of diseases of the eye, the causes of which are not yet known with certainty. Sympathetic ophthalmia provides features of particular interest. The researches carried on in this connection, by v. Hippel and Hegener, show distinctly that the defensive ferments exhibit specific activities. The number of observations is as yet too small to enable us to draw definite conclusions therefrom. In connection with these latter observations we may point out, how important it is to follow up every case, clinically, over a long period, and in no case to pay attention only to the disease which gave rise to the investigation. In particular, the further course of the disease should be followed up in all its phases. We have, in the dialysation process and in the optical method, means which allow us to test the functions of organs over long periods of time.
The observations, which we have here briefly sketched out, will certainly undergo rapid extension in various directions. Perhaps it will be found later on, that there are other explanations than those which have been developed here; and it is highly probable that some of the earlier results, which were obtained
