RE-EXAMINATION OF AN INHIBITOR OF REGENERATION IN TUBULARIA

¹ The Rockefeller Institute, New York, New York, and the Marine Biological Laboratory, Woods Hole, Massachusetts

1. Rose and Rose (1941) found that adult Tubularia hydranths agitated in sea water produced a solution, inhibitor water, which prevented regeneration. They and subsequent workers have ascribed to this inhibitor a role in normal physiological dominance. In the present investigation it has been found that considerable bacterial growth occurs in the solution during the preparation of inhibitor water by the usual methods, and that when antibiotics have been added to maintain bacteriostasis no inhibitor can be collected. Experiments have excluded the possibilities that the antibiotics used are preventing the production of the inhibitor or destroying it as it is produced. It has been shown that metabolites produced by bacterial growth in the absence of hydranths inhibit regeneration.

2. These data lead to the conclusion that inhibitor water represents the by-products of bacterial growth for which the hydranths serve as source of inoculum and as nutritive medium.