755 



always found to extend parallel with or somewhat towards the peri- 

 phery. 



Between the endymal cells of the ental boundary and the den- 

 dritic cells of the ectal boundary of the cinerea there exist intermediate 

 forms which suggest very strongly that they in the course of time 

 will develop into these ectal cells. The intermediate cells have only 

 one process, which is of greater or less length according as the cell 

 is near or far from the alba, this process very rarely divides before 

 reaching the alba and these branches, although they may be traced 

 some distance, are found to have a general trend toward the peri- 

 phery, smaller branches are given off at intervals and these may 

 again subdivide. At the first bifurcation the angle of divergence is 

 very great, generally ninety degrees or even one hundred and 

 eighty degrees; the other divisions are usually at acute angles, 

 there being more or less of an enlargement at the point of bi- 

 furcation. 



The processes are comparatively smooth, the central end of the 

 cell remains smooth and blunt, and the neurite or axis-cylinder pro- 

 cess does not spring from that end of the cell body. In various 

 preparations I have been able to detect a finer branch arising from 

 one of the processes not far from the point of bifurcation or from 

 the peripheral end of the cell itself, which I believe to be the neurite 

 because it could be traced a greater distance than the other pro- 

 cesses, there were fewer branches given off from it, and these were 

 likewise of finer caliber than the neighboring dendrites and left the 

 main stem at greater angles. 



The changes undergone by the cells of the spinal ganglia from 

 the early oppolar or oppositipolar condition to the unipolar have been 

 well demonstrated by von Lenhossek and others. In the cells of the 

 neuraxis of the Desmognathus there is apparently an exact 

 reversal of transition. Starting with the layer next adjacent to the 

 endymal cells we find the unipolar condition, the long process, which 

 may be termed the neurodendrite, extending to the alba. Toward 

 the ectal boundary of the cinerea the neurodendrites become very 

 much shorter until at the very margin of the cinerea the bifurcation 

 of the neurodendrites occurs at the cell itself. The cells lose their 

 pear-shaped appearance as if from ento-ectal pressure and assume a 

 fusiform outline with a process extending from each end. In other 

 instances there has been the appearance of a piriform cell with one 

 of its broad sides facing the alba, from which one or more processes 

 grow out. Since we have, on the ental boundary of the cinerea, cells 



