268 E. VICTOR SMITH 



2. Cerebral ganglia 



a. Ganglion of the ninth nerve. In the goose this gangUon is 

 of large size when compared with that of the chick, the differ- 

 ence in size being due largely to the difference in size of the sen- 

 sory cells rather than to a difference in the number of cells in the 

 ganglion. A careful count of the number of cells was made in a 

 medium longitudinal section of the ganglion of the goose, and in a 

 corresponding section of the ganglion of the chick. The section 

 from the goose ganglion showed 165 cells, that from the ganglion 

 of the chick 160, so that the difference in size does not indicate 

 a relatively larger number of cells. There is a segregation of the 

 cells around the periphery of the ganglion, with irregular clusters 

 of cells in the central portion and areas of considerable size which 

 are devoid of cells. 



The average size of the nerve cells of the ganglia is about 42 

 by 27m. Their major diameters vary between 30 and 69 n and 

 the minor between 19 and 41, 



The nuclei vary from round to elliptical and are of considerable 

 difference in size. Their longer diameters range between 8 and 

 14 m and their shorter between 7 and 11. As observed in cells of 

 other ganglia, the larger nuclei are in the larger cells, the long 

 axis of the nucleus being usually parallel to the long axis of the 

 cell. 



The capsule lies close to the cell wall and the capsular nuclei 

 are numerous and show distinctly. They are rounded to ellipti- 

 cal in outline and have one or two nucleoli. Similar nuclei are 

 scattered rather thickly in the intercellular space and along the 

 processes. Figure 37 represents a typical cell from this ganglion. 



h. The vagus ganglion. In this large ganglionic mass the cells 

 are distributed in elongated clusters, each cluster consisting, as 

 a rule, of a single row of cells arranged with major diameters 

 parallel to the long axis of the ganglion. The number of cells 

 in each cluster is from 3 to 8. The more elongated cells are in 

 greater number around the periphery of the ganglion, and those 

 with major and minor diameters more nearly equal, are more 

 abundant in the central portion. The cells are much more nu- 



