We have presented a series of cases of joint disease where an effort has been carried through to reach a final positive diagnosis. The predominating disease of the series is tuberculosis, because we feel that diagnosis in this is of prime importance. We have shown some of the difficulties in the way of making a positive diagnosis, even where biopsy has been performed. That we should discourage biopsy for this reason is far from our intent, for as we now stand it offers the surest means of diagnosis. The guinea pig test is of value, but in this series has not shown up well, probably on account of the method of inoculating the guinea pigs. Of the other available aids in diagnosis, the tuberculin test deserves first mention, a negative reaction being strongly against tuberculosis. The x-ray in the early cases is of little help, and in complicated cases is of little or no value except to show the extent of the disease. The history and physical examination are of the utmost importance when carefully done, and of great aid, and in a fair proportion of cases give information sufficient to give a correct diagnosis.

There is need of further investigation to improve on present methods of diagnosis, so that we may be able to make diagnosis certain in all cases in the minimum amount of time consistent with immediate treatment in the proper direction.