Abstract
The following experiments were undertaken to see if vitamines extracted from sheep's pancreas and adsorbed in fuller's earth by the method employed by Dr. W. H. Eddy have any effect on the metabolic activities of free cells.
The free living cells used in the experiments were the descendants of a single individual Paramecium aurelia. These were cultivated on half and half pure spring water and 24-hour-old boiled flour water used fresh each day. On this diet the average division rate varied from 1.5 to 2.0 divisions per day at the time the vitamine tests were started.
The vitamine-bearing fuller's earth was kept in capsules prepared by Dr. Eddy. A small dose of this was obtained by moistening the point of a needle in the Paramecium culture water and dipping this in the capsule. The adhering granules were then shaken off in the culture water.
It was necessary at first to determine whether or not the fine granules of the fuller's earth would be ingested by the Paramecium. For this purpose sterile spring water was used with the earth. It is well known that similar granules of carmine or indigo will be ingested and a few preliminary tests showed that the granules of fuller's earth are similarly taken in and stored in the gastric vacuoles. To be doubly sure of this a quantity of the fuller's earth was stained with neutral red, washed and then supplied as before to Paramecium. The bright pink granules in the resulting gastric vacuoles left no doubt that the Paramecium will ingest the vitamine-bearing granules.
The individual Paramecium to be studied was isolated in a watch glass containing one drop of Great Bear water, one drop of boiled flour water which has been exposed for twenty-four hours, and the usual dose of vitamine-bearing fuller's earth.
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