276 E. VICTOR SMITH 



The processes, so far as observed, follow a direct course after 

 they emerge from the cell. The delicate capsule and its elliptical 

 nuclei are clearly shown. 



The ganglia of the lumbo-sacral region have the cells arranged 

 in rows. There is a less marked division of the cells into two 

 classes, since many cells of intermediate size occur, forming transi- 

 tion stages between the large and the small cells. The spinal 

 gangha outside of the brachial and lumbo-sacral regions vary 

 somewhat in size, although all are small. There is a slight tend- 

 ency toward arrangement of the cells into elongated groups. 

 The cells are distributed fairly uniformly throughout the ganglia. 



The majority of the cells are rounded to elliptical, a number 

 are pear-shaped, and the remainder are- irregular. One of the 

 largest cells measured 38 m in length and 26 in breadth; while one 

 of the smaller ones was 20 ^ long and 12 broad. The nuclei are 

 large, and in shape, round to elliptical, most of them being rounded. 

 They are, as a rule, centrally located and in each was observed a 

 large, clearly defined nucleolus. 



2. Cerebral ganglia 



a. Ganglion of the ninth nerve. In the pigeon this ganglion is 

 very small, being less than 0.2 mm. in diameter, and a little less 

 than 1.5 mm. long. The cells are distributed fairly uniformly 

 throughout the ganglion. They are not close together nor is 

 there any tendency towards arrangement in rows. 



The cells are round to elliptical with here and there some that 

 are oval, elongate, and irregular. The cells are relatively small, 

 one of the largest observed being 16 by 27 fx. One of the smallest 

 cells measured 16 ^ long and 11 broad. 



The nuclei are relatively very large. One of the largest cells, 

 16 by 27 m, had a nucleus that was 14 n long and 11 broad. A 

 cell of average size, 16 by 19 n, had a rounded nucleus 11 m in 

 diameter. The nuclei were usually near the center of the cells, 

 but not infrequently they were near the walls of the cells. The 

 nuclei contain one very large nucleolus. 



h. The vagus ganglion. In the pigeon this ganglion is less than 

 0.5 mm. in diameter and about 1.5 mm. long. The cells lie 



