164 S. WALTER RANSON 
estimate they might be said to represent together about 3 per 
cent of the total number in the spinal ganglia of the dog. In the 
horse, according to v. Lenhossék, they are very much more 
numerous. 
5. Cajal’s ‘fenestrated’ cells are characterized by the presence 
of excavations in their substance. These are most commonly 
found in the neighborhood of the origin of the axon, where they 
often cause a U-shaped mass of protoplasm to be raised from 
the surface of the cell. The axon usually arises from the sum- 
mit of such a loop. Fig. 8 shows a simple cell of this kind and 
fig. 9 a more complicated one. These excavations are filled with 
small cells, ‘subcapsular or satellite cells.’ It is only in the poorer 
of the pyridine silver preparations, however, that these satellite 
cells are stained. Dogiel was unable to find the fenestrated cells 
in his preparations—and concluded that Cajal had seen and 
wrongly interpreted certain cells of our type Iv. 
Indeed it seems that among his fenestrated cells Cajal has 
figured and described some which more properly belong with the 
cells of the preceding variety. There is, however, a group to 
which the term ‘fenestrated’ properly applies, such as those seen 
in figs. 8 and 9. In these the network is formed by protoplasmic 
loops, while in figs. 5, 6 and 7 the axon is itself broken up to form 
the network. In the fenestrated cells the axon is usually smaller 
than the protoplasmic loops from which it arises, while in the 
other varieties the size of the fibers forming the network is always 
smaller than that of the axon and depends upon the number of 
such fibers into which the axon has been split. 
In addition to the cells of the varieties just enumerated, one 
bipolar and two multipolar cells were seen in the sections of the 
spinal ganglia of the dog. Fig. 10 represents a multipolar cell 
with short, club-shaped processes, and fig. 11 a cell of Dogiel’s 
type x1, which, according to his more complete pictures, possesses 
many medullated processes which divide repeatedly, breaking 
up into fine branches with expanded ends. 
According to Nageotte (07) the fibers ending in end bulbs 
resemble those seen in large numbers in transplanted ganglia and 
are therefore to be regarded as being the product of regenerative 
