It will be seen that seven cases of “dementia paralytica” were examined, and that in six of these spiroch were found by the darkground method, although when sections of these positive cases were cut the organisms were only detected in three. It is thus obvious that the latter method presents much greater difficulties than the former, the spiroch being found only when they are numerous. Five cases also were examined in which the symptoms suggested a diagnosis of “dementia paralytica.” This diagnosis was, however, found on section to be incorrect. No spirochaetes were found. These results do not illustrate the distribution of the spirochaetes over the whole cortex, because specimens were sent from a few regions only. It was, however, usual to find the organisms in all specimens sent when success was obtained with one. All the cases examined had exhibited relatively acute manifestations before death, and the brains with one exception were not markedly wasted. The lesions on the whole appeared to be recent. As already mentioned the spirochaetes were always confined to the grey matter; in one case only was a single specimen seen in the meninges. They were more or less superficial, and no constant relation could be observed between them and nerve-cells or blood-vessels. Some spiroch indeed appeared to be applied to nerve-cells, but this distribution was not striking. Further no connexion was apparent between the organisms and cellular infiltrations; indeed they appeared to be scattered quite fortuitously about the superficial layers of the cortex. It may be remarked that the drawings by Mr. J. B. Ford give an extremely accurate impression of the appearance of the sections under the microscope.