NERVUS FACIALIS OF ALBINO MOUSE 113 



In the tongue the Ungual nerve passes forward midway be- 

 tween its lateral edge and the median septum. One branch is 

 given off immediately after the nerve enters the tongue. This 

 passes dorsally and posteriorly to supply the area in front of 

 that supplied by the glossopharyngeal nerve. The remaining 

 branches arise irregularly and supply all of the tongue in front 

 of this area. Some of the branches extend laterally, some to the 

 ventral surface, but the larger and most numerous branches pass 

 to the dorsal surface. In the ventral part of the tongue a few 

 small branches join those of the hypoglossal nerve, and a few 

 others end in an undetermined manner among the muscle fibers. 

 The majority of the branches, however, could be followed to the 

 mucous membrane. 



In the series studied the taste-buds are located in both walls 

 of the valley around the circumvallate papilla, in the foliate 

 papillae, in a small area of the cheek opposite the foliate papillae, 

 and irregularly scattered over the dorsal surface of the tongue 

 in the area supplied by the lingual nerve. There are no scat- 

 tered taste-buds in the area supplied by the glossopharyngeal 

 nerve nor along the sides or the ventral surface of the tongue. 

 In the area supplied by the lingual nerve there are thirty-six 

 taste-buds in one-half of the tongue. These are widely separated 

 posteriorly and become more numerous as the tip of the tongue 

 is approached. Each of them is placed near the surface of the 

 epithelium on the top of a flat tunica propria papilla. 



One or two bundles of nerve fibers from the lingual nerve were 

 followed into the bases of the papillae on which the taste-buds 

 are located. In the papillae these fibers break up into a number 

 of branches and form an intricate complex of very fine fibers. 

 From these plexuses sonje fibers pass into the taste-buds. Other 

 fibers pass into the surrounding mucous membrane, so that the 

 taste-bud and a considerable area of the mucous membrane is 

 supplied from the plexus in each papilla. 



The most striking feature of the nerves within the tongue is 

 the large number of ganglia and ganglion cells along them. The 

 majority of these cells are in clumps or microscopic ganglia along 

 the nerve bundles. Along the glossopharyngeal nerve there are 



