328 S. W. RANSON AND P. R. BILLINGSLEY 
branch and intertwine (fig. 5, a). All transition stages are found 
between the simple glomeruli and the dendritic crowns. When 
the glomerulus is located on the side from which the axon arises 
it may be prolonged out for a short distance along the axon, 
giving rise to a comet-shaped formation. 
The glomeruli formed from the dendrites of more than one 
cell may be called composite glomeruli and are somewhat more 
complicated than the simple glomeruli just described. The 
large subcapsular dendrites of two or more cells converge toward 
each other to form a circumscribed mass of branching and inter- 
lacing dendrites. Figure 6 gives a good idea of a tricellular 
glomerulus, which, along with the three cells, seems to be en- 
closed in a single capsule. The capsules and subcapsular satel- 
lite cells are not well differentiated in pyridine silver preparations, 
but, according to Cajal, the glomeruli are surrounded by a cap- 
sule that separates them from the fiber bundles. The capsule is 
better defined in the bi- and tricellular than in the multicellular 
forms. 
The fine black fibers seen interlacing with the dendrites in 
figures 5 and 6 are the branches of axons and will be discussed 
in another place. 
The extracapsular dendrites pierce the capsule and run for 
longer or shorter distances among the cells, helping to form an 
intercellular plexus of dendritic and axonic ramifications. ‘The 
cells of the superior cervical ganglion of the dog and cat are pro- 
vided almost exclusively with this type of dendrite. Such dendrites 
are also numerous in this ganglion in man. Here they may come 
from cells devoid of subcapsular processes (fig. 5, 6) or from cells 
provided with dendritic crowns or glomeruli (fig. 5, a). They 
are usually coarse fibers and may branch near the cell or may 
remain unbranched until they leave the section. Often it is 
possible to trace them much longer distances than is indicated 
in the figure, but in no case could they be followed to what seemed 
to be their true termination (fig. 7). Cajal differentiates three 
types of cells in the human superior cervical ganglion: 1) cells 
provided exclusively or almost exclusively with subcapsular 
dendrites; 2) cells provided only with long dendrites, and 3) 
