Figure 14 represents a _sphaeronucleosus_ with a small particle attached to the middle of the upper surface of the ameba. As the ameba moves forward, shown by successive outlines, the particle likewise moves forward, but, as will be observed, at a more rapid rate. Measuring the distance from particle outline 1 to 4, and from ameba outline 1 to 4, it is seen that the rate of movement of the particle compares with the rate of movement of the ameba as 2.48 to 1. [Illustration: Figure 14. Illustrating the movement of a particle on the upper surface layer of an _Amoeba sphaeronucleosus_. Length of the ameba, 120 microns.] [Illustration: Figure 15. An _Amoeba sphaeronucleosus_ with two particles attached to its upper surface film, one in the middle and one at the side. _a_ moved 2.6 times as fast as the ameba while _b_, lying nearer the side, moved only 1.9 times as fast as the ameba. Length, 100 microns.] Particles lying near the side do not move forward as rapidly as those lying in the middle. Figure 15 shows two particles, one of which, _a_, lying near the middle of the ameba, moved 2.6 times as fast as the ameba advanced in the region of the particle; while particle _b_ moved only 1.9 as fast as the ameba in front of the particle. The speed ratio of particle _a_ to particle _b_ was as 1.26 to 1. [Illustration: Figure 16. Illustrating more rapid movement of the surface film in the middle of _Amoeba sphaeronucleosus_ than near the edge. The vertical lines connecting the particle with the ameba outlines were drawn only for convenience of reference. Length of ameba, 120 microns.] Figure 16 shows a particle lying still more to the side than in the preceding figure. In the first six stages the particle moved 1.85 times as fast as the ameba. The particle then came to the edge. From stage 7 to 10 the particle moved more slowly than the ameba. At stage 11 the particle had come to lie in the posterior half of the ameba, where the tendency of the surface layer is to travel toward the middle of the upper surface. In stage 12 the particle had gotten away from the edge of the ameba and already shows a gain in speed. From stage 13 to 16 the particle moved again about 1.83 times as fast as the ameba. But at stage 16 the edge was reached with a consequent decrease in speed of the particle. The direction of the path described by a particle carried on the back of an ameba depends upon what part of the ameba is most rapidly forming ectoplasm. That is, the particle tends to [Illustration: Figure 17. Illustrating the different speeds with which particles move when attached to the surface film of an _Amoeba sphaeronucleosus_, depending upon their location. Particle _a_ moved 3.5 times as fast as the ameba and _b_ 2.7 times as fast. Length of ameba, 110 microns.]