NERVUS FACIALIS OF ALBINO MOUSE . 89 



cells scattered among the others. They are of the unipolar type 

 in which the single process is convoluted and twisted around the 

 cell body (Ranson, '12, type 1). No collaterals ending in end- 

 bulbs were seen, although this type is particularly numerous in 

 sections of the human geniculate ganglion in my possession. It 

 was at first thought that the absence of these might be due to 

 the fact that they had not developed. Huber and Guild ('13 b) 

 found them in the spinal ganglia of three-day-old rats and they 

 are present in the semilunar and spinal ganglia of my mice. It 

 is probable, therefore, that they are few in number or absent in 

 the geniculate ganglion of the mouse. 



That the geniculate ganglion belongs to the cerebrospinal 

 type of ganglia and is composed of unipolar cells was first estab- 

 lished by Retzius ('80) and has since been confirmed by von 

 Lenhossek ('94) and Weigner ('05). 



2. Nervus intermedius 



Between the geniculate ganglion and the brain the nervus in- 

 termedius is composed of two parts, the larger contains those 

 fibers which come from the interior of the geniculate ganglion, 

 the smaller being a separate efferent root of the nerve (fig. 1). 



The fibers from the ganglion leave it in two distinct bundles. 

 The more laterally placed and smaller bundle (figs. 1, 2, and 3, 

 N.Int.l.) leaves the upper border of the main part of the ganglion 

 and passes dorsally and medially anterior to the dorsal part of 

 the ganglion. At the dorsal limit of this part of the ganghon 

 this bundle makes an abrupt bend posteriorly and extends 

 through the vestibular ganghon (fig. 2) . Leaving -this ganghon 

 it passes on to the dorsal surface of the motor part of the facial 

 nerve and is joined by the other bundle (fig. 1). 



There is apparently some mixing of fibers during the passage 

 of this bundle through the vestibular ganglion. Whether there 

 is an actual interchange of fibers in the form of anastomoses could 

 not be determined. It is certain, however, that there are no 

 large contributions from one to the other, for the difference in 

 the size of the fibers would make possible the detection of such. 



