26 OLOF LARSELL 



in the mule, and the relation of the nerve to the adjacent blood- 

 vessels shown in cat, mule, and beef, suggested strongly that 

 the nervus terminalis is composed, at least in part, of sympa- 

 thetic fibers. There remains the possibility, which could not be 

 adequately tested in the available equine or bovine material, 

 that there may be a general or special sensory component, in 

 addition to the motor and sensory sympathetic fibers which 

 were found. It was accordingly deemed advisable to make as 

 thorough a study of the terminalis ganglia and of the fibers con- 

 nected with them in the cat as the material available would 

 permit. 



The fact that the nerve is situated in a position so difficult 

 of access, together with its small size, and the further circumstance 

 of its relation to the cribriform plate, made necessary a technique 

 permitting of decalcification, so that nerve and ganglia might 

 be studied in situ. For this reason, chiefly, the pyridin-silver 

 method, as previously described, was employed. 



There was considerable variation in different parts of the same 

 section in the intensity and clearness of the impregnation. It 

 was also found that, in general; the cells of the smaller ganglionic 

 clusters were much better differentiated from the background 

 than were those in the more crowded larger ganglia. Because 

 of this fact the majority of the cells figured are from the small 

 clusters of cells, but for comparison, considerable attention was 

 paid to the large ganglionic mass (figs, 1, 2 and 3, gn.) which 

 appears to correspond with the 'ganglion terminale' of authors. 



Types of ganglion cells. Figure 5 represents a typical small 

 ganglionic mass which had its position in the meninges covering 

 the mesial side of the olfactory bulb. It lay slightly caudad to 

 the ganglion terminale and a little more ventrally. This clus- 

 ter was similar to numerous others scattered throughout the 

 plexus. Such clusters of cells are usually situated at the meet- 

 ing point of several small strands of fibers which converge from 

 various directions. The group of cells figured represents only 

 a portion of this particular ganglionic mass. The remaining 

 portion was to be seen in the next section of the series. 



