Of the annual output of the lobster canneries of the Maritime provinces, a large number of the cans are found immediately or ultimately with the contents darkened or blackened, and the inner surface of the tin in such covered wholly or in part with a rust like deposit. To what this discoloration is due has been variously explained out almost wholly as of purely chemical origin, yet the explanation advanced have not in the slightest degree assisted in suggest. measures to prevent discoloration. Recently it has been found that the effected cans examined had in every instance bacterial flora which the unaffected cans did not have. generalization as to the cause of the discoloration be drawn from these results t be determined after further extended investigation. If the causation should prove to be bacterial in character, the measures to be taken counteract it would be comparatively simple and would involve only thorough sterilisation of the cans after they are hermetically sealed.