Although the above facts are well established, the more important question is, What is the origin of these fibers and how do they get into the nerve trunks in which they are found? To make this matter clear a word must be said about the general nature of sensory nerve paths. The connection between a sense organ and the brain consists of a series of separate links, which always remain distinct units. Each cell, or neurone, as one of these units is called, consists of a body, which contains the nucleus, and two sets of branches. In one set the branches are very short and numerous, called dendrites; in the other there is usually only one branch, called the axone, which is relatively long. A group of cell bodies is called a ganglion. In practically all sensory nerves these ganglia are situated outside of the central nervous system. The ganglia of the spinal nerves are located just outside of the spinal cord and are called simply spinal ganglia. The ganglia of the cranial nerves usually receive special names. Thus, the ganglion for the great trigeminal, or fifth, nerve is called the gasserian ganglion. Of the two for the glossopharyngeal, or ninth, nerve that one of interest to us is called the petrosal ganglion. The vagus has two ganglia, an upper and a lower; the former, or jugular, ganglion is involved in the sense of taste. From these ganglia the branches called the dendrites pass to the sense organ and are found twining around the taste cells in the taste buds. The other branches, the axones, pass into the brain stem and finally end in some brain center. The question, then, is, Do the taste fibers which are found in the lingual branch of the fifth nerve have their cell bodies in the gasserian ganglion, do those found in the ninth nerve have their cell bodies in the petrosal ganglion and those found in the tenth nerve have their cell bodies in the jugular ganglion? These are indeed difficult questions to answer. Reliance must be placed largely upon the results of surgical operations upon these nerves and ganglia, with their resulting effects upon the sense of taste. Earlier reports of surgical operations in which the gasserian ganglion was removed were that the taste sense on the tongue was completely destroyed, suggesting that all of the gustatory fibers of the tongue had their origin in the gasserian ganglion. Later reports, however, were that only the taste sense of the anterior two-thirds of the tongue was destroyed by this operation, suggesting that the fibers found in the glossopharyngeal nerve were independent of the gasserian ganglion and really had their origin in the petrosal ganglion, these fibers getting into the lingual branch of the fifth nerve by a circuitous route.