From the very beginning of the study of protoplasm, biologists and cell physiologists have been concerned with the attempt to understand as much as possible about its physical state. But it is doubtful if in any other field of biology there has been more erroneous information gathered and perpetuated. This has in part been due to a lack of understanding of basic physical facts, in part also to the publication of numerous careless and untrustworthy observations. Microdissectionists prodded the cell with their microneedles, and they made many definite statements both concerning the relative and also the absolute viscosity of the protoplasm they attacked. These observations were completely subjective and were in addition handicapped by the fact that when a needle or other foreign object enters a cell, it is almost certain to cause a clotting of the protoplasm in its immediate vicinity. One observer saw no Brownian movement in the protoplasm of marine egg cells and concluded from this that the viscosity of the protoplasm of these eggs must be as great or greater than that of glycerol, in which he assumed no Brownian movement possible. And this in spite of the fact that numerous observers have noted vigorous Brownian movement in such eggs, the amplitude of the movement being limited by the fact that the cell is so clogged with granules that the distance any one granule can move is restricted.