SOME EFFECTS OF THE LOWER ALCOHOLS ON PARAMECIUM

¹ ZOÖLOGICAL LABORATORY OF THE JOHNS HOPKINS UNIVERSITY

1. A mixture of B. lactis aerogenes and B. aquatiis (sp. ?) constitutes the best food found for Paramecium.

2. When paramecia are exposed to an alcohol in sufficient strength they are at first incoördinated in movement and then inactivated. Later toxic effects are manifested by marked internal changes, formation of "blisters" by elevation of cuticle, rupture of ectoplasm, and death.

3. The anterior end of Paramecium is more susceptible to alcohol than the posterior end, and the aboral side more than the oral.

4. Indirect daylight has no perceptible effect on normal or alcoholized paramecia, but direct sunlight inactivates them; this effect is augmented in the presence of alcohol.

5. Change in temperature over a wide range has no appreciable effect on the susceptibility of paramecia to alcohol.

6. Aëration and agitation of a Paramecium culture renders the paramecia much less susceptible to alcohol.

7. Paramecia in a given solution without food live longer with alcohol than without; starving cultures can even be restored to prosperity by the addition of suitable amounts of any alcohol.

8. Exposure of paramecia to weak ethyl alcohol increases their susceptibility to a stronger dose of ethyl alcohol, and to five other alcohols.