Morpho‐Physiological Study of Ameboid Movement. 3. Invisible gel structures in the endoplasm of an ameba of the verrucosa type

SYNOPSIS. A small ameba of the verrucosa type has a flattened and fan‐shaped body, at the broadest front of which there is formed a distinct hyaline zone. Along the lateral borders thereof there is a thin optically indistinct but rigid body wall, which can be determined by means of cine‐micrographic analysis of the positions of granules in and near it, and their movements. Its caudal portion is well differentiated from the rest of the body and was identified as a region of complicated conditions, manifesting solating activity, contractility, ejection, formation of caudal pseudopods, and continuous shifting of its minute components. The tracks of moving endoplasmic granules were plotted to determine their individual irregularities in velocity and direction of movement. These tracks suggest the existence in the endoplasm of small to large motionless gel structures derived from the frontal hyaline zone, which is therefore postulated to be heterogeneously gelate as a whole. Judging from the fact that granules carried by the protoplasmic matrix passed through these so‐called gel areas, it is proposed that the source of the motive force of ameboid movement may be in the advancing edge of the clear frontal zone where gelation is vigorously taking place.