It does not seem unreasonable to believe that the entire group of so-called self-limited diseases, including among others the exanthemata, pneumonia, acute rheumatism and chorea are dependent upon bacterial invasion. The dependence of many of these upon specific bacteria has already been demonstrated and it is not improbable that the near future will bring similar demonstration for the remainder. The list of the former is steadily growing, while that of the latter is correspondingly diminishing. Among the latest of the disorders which have been shown definitely to owe their origin to microörganismal activity is mumps.
Pasteur noted in the blood of patients suffering from this disease bacilli 1 μ thick and 2 μ long. Capitan and Charrin, and also Ollivier, observed in the blood and in the urine of such patients small rods in addition to cocci. Boinet found in the blood cocci arranged in part in pairs and in