In previous papers it has been contended by Dr. Douglas McRae, Dr. Dods Brown and myself, that in cases of general paralysis there are special bacterial infective foci in the nasopharyngeal and buccal mucous membranes, and that these infective foci are of importance in the pathogenesis of the disease; Dr. McRae and I have also maintained that in cases of tabes dorsalis there are similar infective foci in the genito-urinary tract. In this paper I wish to deal with some further investigations, the results of which give additional support to these views. In the fifteen minutes at my disposal it is impossible for me to describe these investigations in detail. I can only indicate their chief results and state some of the conclusions that they seem to me to warrant. All the evidence that I can lay before the meeting is shown under the ten microscopes on the tables.