In _Frontonia leucas_, another large ciliate, rotational streaming is under the control of the organism, and special use is made of it in feeding. _Frontonia_ feeds mostly, if not entirely, on large particles. It has no oral groove like paramecium has, and when swimming no ciliary vortex is produced such as is seen in paramecium. _Frontonia_ feeds mostly by “browsing,” that is by eating particles lying on or against some solid support, though it is able also to feed upon particles suspended in the water. _Oscillatoria_ and _Lyngbia_ and other filamentous algae are the chief food of _Frontonia_. Filaments of these algae are ingested by pulling them into the mouth and then rolling them up into a coil in the body. Pieces of _Oscillatoria_ six to eight times as long as the _Frontonia_ are readily eaten in this way. As a rule the end of a filament is seized by the mouth and gradually passed back into the body (Figure 32, _a_). As soon as the tip of the filament is well in the mouth and in contact with the endoplasm, streaming begins in the endoplasm in the region of the mouth and takes a direction directly back against the aboral wall, almost, if not quite perpendicular to the longitudinal axis. This stream of endoplasm carries the filament back to the aboral wall, sometimes pushing out the wall a considerable distance. Presently, however, the filament is carried posteriorly along the aboral wall by the streaming protoplasm, which has by this time become rotational, and after reaching the posterior end the filament is brought up along the oral wall. The rotational streaming continues until the entire filament is wound up, which in exceptional cases may make four or five coils inside the animal. The mouth has considerable grasping power. This is shown in Figure 32 where a filament of _Oscillatoria_ was bent upon itself by the mouth and then rolled up in the body by the endoplasm in the same manner as a single filament. The mere viscosity of the endoplasm would be insufficient to bring about the bending of the filament. For the sake of comparison it should be added that a similar grasping power is also present in paramecium. The moment the food vacuole at the mouth is large enough, the endoplasm pulls it away and moves it rapidly toward the posterior end of the paramecium, much more rapidly than it would be carried by the rotationally streaming endoplasm. But from the posterior end forward the food vacuole is carried at the same rate as are the other particles in the endoplasm. In both _Frontonia_ and paramecium rapid endoplasmic streaming precedes for a short distance the forward end of the ingested filament or the food vacuole (Figure 32, _a_).