But in the case of a close relative of the ameba, the one-celled animal known as the paramecium, union with another paramecium, true conjugation, has been proved necessary to prevent death sooner or later.
"The Glands Regulating Personality"
Louis Berman, M.D.
A few years ago Calkins and Eddy tried to determine the effect of the vitamine on the single cell by use of the paramecium but the results of the experiments failed to show a vitamine requirement on the part of these animals.
"The Vitamine Manual"
Walter H. Eddy