So far as concerns the resemblance between the tubercle and lepra bacilli, we must not omit to mention that one almost always finds among tubercle bacilli some which are pretty long and somewhat bent; this is never the case among lepra bacilli. Baumgarten has indicated as a distinction between them, the fact that the latter is more easily stained; according to our experience this distinction can scarcely be regarded as sufficient. But the distribution of the bacilli in the tuberculous and leprous tissue is usually so very different, the tubercle bacilli being usually arranged singly, the lepra bacilli always in large quantities in masses and clumps, that a confusion of the two diseases anatomically can only be possible in exceptional cases. Danielssen has repeatedly stated in his triennial report of the Lungegaards Hospital that tuberculosis and leprosy are such nearly allied diseases that the one (leprosy) may pass into the other (tuberculosis) by a modification of the bacilli, and that thus the frequent combination of the two diseases is to be explained. This view we cannot, in view of the above demonstration, support. If an organ is attacked at the same time by tuberculosis and leprosy, one can anatomically very readily separate the two diseases. We would rather seek the explanation of the frequent combination of the two diseases in our institutions in the great over-crowding and consequently insanitary conditions to which they were formerly subjected. Tuberculosis once introduced, we find a ready explanation in the bad habits of the patients in regard to expectoration, why it was difficult or impossible to root it out. In later years, when the institutions are no longer full and the sanitary conditions consequently much improved, tuberculosis has much decreased. Whether tuberculosis was as frequent a combination in the country as in our institutions we do not know. The duration of life of patients in the country is about a year longer than in our institutions, and possibly this depends on the absence of tuberculosis.