The effects of X-radiation on the reconstitution of Stenostomum tenuicauda and some other worms

1. Laboratory-grown specimens of Stenostomum tenuicauda were subjected to large dosages of unfiltered X-radiation and the effect upon their reconstitutional behavior following operation noted. For comparison, similar observations were made on Dero limosa and Pristina longiseta.2. Maximum dosages of approximately 30,000 R units, applied over an interval of nine hours, and of approximately 20,000 R units applied in 36 minutes had no apparent effect on normal reconstitution in Stenostomum. The lethality of the latter dosage was indicated by the disintegration of the completely reconstituted worms and of isolated un-operated worms four days after the irradiation.3. Anterior head regeneration in Pristina was inhibited following an apparently non-lethal dosage of 20,000 R units applied over a period of four and a half hours. Specimens of Dero were cytolyzed by the same dosage.