4

The cases of Mediterranean fever which have come under our investigation
at the present time naturally fall into two groups :

      (a) those in which M. Melitensis was isolated from the spleen during life; and,

      (b) those in which no splenic puncture was made, the diagnosis resting solely
      on the clinical history and the serum agglutination reaction.

      Group a.—The cases in this class number eleven. In these cases a few
drops of blood removed from the spleen during life with a sterile syringe were
spread over several agar tubes. This simple operation was done under our
written instructions by the medical officer in charge of the case. The agar
tubes thus inseminated were at once returned to the laboratory, where the
further examination of the growths was made. In nearly every instance a pure
culture of a coccus, presently to be described, was obtained. In one or two
cases only were there any contaminating organisms and these were evidently skin
cocci of different kinds. No difficulty, however, was ever met with in isolating
the specific organism from these tubes.

      From all the cases which gave a serum agglutination reaction with
M. Melitensis and in which splenic puncture was made there was isolated from
the spleen, by the method described, a small coccus which presented the following
characteristics, which are regarded by the workers on the Commission for the
investigation of Mediterranean fever as justifying the organism being with
confidence regarded as M. Melitensis :—

         (1) A slow growth at 37° C. on agar slopes; discrete colonies are circular,
         transparent and dew-like; the complete surface-growth is greyish-
         white and moist; when cultures are old the growth often acquires
         a yellowish-brown colour.

         (2) Stained by weak carbol-fuchsine shows a small coccus or cocco-bacillus,
         appearing mostly as diplo-cocci and in short chains.

         (3) Stained by Gram-Weigert method does not retain its stain.

         (4) Grown in litmus milk, there is no development of gas, acidity or coagula-
         tion, but there is a production of alkalinity.

         (5) Grown on glucose-litmus agar there is no production of acidity, but
         production of alkalinity.

         (6) Agglutinated and sedimented with the serum of an animal immunised
         with a pure standard growth of M. Melitensis.

         (7) In the case of two of the races isolated a typical infection of a monkey
         was produced.

      To points 6 and 7 we shall return later. Having, therefore, stated that the
various strains of M. Melitensis isolated by us responded to the above tests, we
may now consider the cases from which this organism was isolated more or less
in detail.