Most bacteria react sharply to a minute change of a medium so that the growths are influenced. Such a property is, however, different according to the bacterial species. A medium shows a clear-cut difference in the growth of certain bacteria but in others. V. cholera-- and S. typhi grow well in ordinary peptones and the digests of cuttlefish.
The present report concerns the comparisons of the disests of cuttlefish with the various peptones quantitatively upon cultivation of V. cholerae and S. typhi. The results of these experiments are as follows:
1. Among the digests prepared with papain, pepsin, and pancreatin the papaic digest of heated cuttlefish was superior to the other digests, a commercial peptone, and proteose-peptone upon cultivation of V. cholerae. Its susceptibility to V. cholerae was similar to the effect of nutrient agar on the solid media.
2. The growth of S. typhi decreased in the papaic digest of cuttlefish, as compared with tryptose, Bacto-peptone, proteose-peptone, tryptone, which increased.
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