In the flesh, on the ventral side of the Brachion, there is a deep cleft, the edges of which as well as the whole interior of a tube of which it is the orifice, are thickly covered with vibratile cilia. This tube leads to a mouth with powerful jaws of unwonted structure, which is so deeply sunk in the tissues of the body, that it never comes into contact with the water. It opens into a gullet leading to a stomach, intestine, and vent, at the posterior end of the body. The vibrations of the cilia on the lobes of the animal’s head form two circular currents in the water, like whirlpools, which draw all floating particles into their vortices, and the streams from the two whirlpools uniting into one current, flow off horizontally and pass immediately over the slit on the ventral side of the animal. Some of the floating particles are arrested by the cilia on the edges of the slit, and are drawn into the sunken mouth by the vibrations of the cilia in the tube. The edges of the slit act like lips, and seem to possess the sense of taste, or of some modification of touch, which enables them to select from the particles presented to them, such as are fit for food; these are admitted into the mouth, where they are bruised by the powerful jaws. The mouth or masticating apparatus is the most extraordinary and complex part of this animal. It consists of two horny toothed jaws, acting like hammers upon an anvil. The two hammers, which approach each other from the dorsal sides of the body, are each formed of two parts united by a hinge; the first parts correspond to the handles; the second parts, which are bent at right angles to the first, resemble hands with five or six finger-shaped teeth united by a thin membrane. The teeth are parallel to one another when they meet on the anvil, and are seen through the transparent mass tearing the food into fragments. Some of the Rotifers resemble the Errant Annelids in being able to turn this complicated machine inside-out through the ciliated tube and slit, so as to bring it into contact with the water. When the food has been masticated it is sent into the stomach, where it is digested. The whole of this process is seen through the transparent and colourless body of the Brachion, because its favourite food is the Syncryn velox, a minute bright green plant, which from its active motions was at one time believed to be an animal.