260 E. VICTOR SMITH 



ity of those issuing from the sides of the cells turned distally after 

 a very short course. In these counts few implantation cones 

 (fig. 13, impl.c.) and few (2 out of 481 cells) initial glomeruli were 

 seen. 



The ganglion cells of the old hen and of the spring chicken 

 showed interesting differences. While in the old hen, the pe- 

 riphery of the cells was shrunken and crinkled, in young birds, 

 the cells were more uniformly rounded and plump (see also under 

 Gasserian ganglion). Few fenestrations and protoplasmic slings 

 were observed in the young bird but were not uncommon in the 

 old hen. Figure 9 shows a cell of the vagus ganglion of the old 

 bird with fenestrations (fe^i.) and small protoplasmic slings (slg.). 

 Surrounding this cell there is a pericellular network (pr.cL). 



The pericellular fibrous structures in this ganglion are of two 

 kinds. One is a true network in which fibers branch and anasto- 

 mose (figs. 10 and 14, pr.cL). The other is shown in figure 

 10,^; it is not a true net, but like a thread running several times 

 around the cell, from which fibers extend into the intercellular 

 space (fig. 10, fbr.). The pericellular networks do not come in 

 contact with the cell but lie close to the capsule. 



Bundles of non-medullated ('afferent') fibers, probably from 

 the sympathetic system, ramify among the cells of the sensory 

 ganglia. Figure 13 fairly represents the situation. This is a 

 sketch of part of a section from the peripheral region of a vagus 

 ganglion of the old hen. The large bundle (L) ran into one of 

 the roots of the vagus; it showed in four consecutive sections and, 

 accordingly, was not less than 36 ^ in thickness. The figure 

 shows the cut ends of the larger number of these fibers as they 

 curved upward to pass over the cells that lie in their path. Some 

 of the non-medullated fibers joined the irregular network about the 

 cell marked b. A number of the fibers of the intercellular space 

 were also connected with this network. The network extended 

 about the process but was entirely confined within the capsule. 



c. The Gasserian ganglion. The Gasserian is the largest of 

 the sensory ganglia found in the chick, and shows marked com- 

 plexity in the arrangement of its elements. Large bundles of 

 fibers pass through the ganglion without being connected with the 



