Calkins and Lieb ( I ) made some experiments with alcohol on paramecia and found that " . . . alcohol has no effect when taken in too weak doses, and too powerful an effect when taken in over strong doses." " . . . when a medium dose is given (for
W. A . Matheny
T h e single-celled animals are especially well adapted for the investigation of physiological activity. T h e ease with which they lend themselves to experimental methods and the simplicity of their structure make i t possible to arrive a t an accurate analysis of the effects of the stimulus in question.
This problem was suggested by Prof. C. F. Hodge under whose direction a series of similar experiments are now being carried on.
Methods
Hay infusion was used a t first as a culture-medium, but later i t was found that alfalfa, on account of its uniformity, gave much better and more reliable results. A comparison of these culturemedia is given in Table I .
T h e infusion was made as follows : Fifteen grams of hay or alfalfa were boiled for one minute in 1500 cc. of tap water. This was prepared each day late in the afternoon and was used the next morning.
A "wild" paramecium was taken from a hay infusion in laboratory and placed in a watch glass in 8 cc. of fresh solution. At the end of twenty-four hours the hay solution was renewed. O n the second day there were parameciaenough present to start the experimen t.
At first, six cultures, each comprising four lines, were carried.
Afterwards others were added. Using a pipet drawn out to a fine point, four individuals were transferred to four depression slides, each having a capacity of about five drops. Pure infusion was added and this started the control culture. In a similar manner cultures were started in the following petcentages of alcohol, I per cent, & per cent, 2s per cent, & per cent, &* per cent.
A few days later cultures were started in 2 per cent, 3 per cent, 4 per cent, 5 per cent, and 6 per cent solutions.
In order to determine the resistance of paramecia to alcohol in greater quantities, the following experiment was performed. An individual was taken from the control and isolated in pure infusion. When it had made three divisions, a culture of four lines was started in pure solution for control. Another culture of four