966 
epithelium is not visible in any single section. The appearance of 
the dorsal motor vagus nucleus is not constant in its most spinal 
portion, its first appearance is followed frontally by several sections 
calamus 
frontal <— —> spinal 
Phocaena communis fig. 1. 
Dorsal motor vagus nucleus. 
in which not one cell is to be seen. Spinally from the commencement 
we see cells at about the same level, and these might be erro- 
neously taken to be cells belonging to the nucleus in question. A 
careful examination however, shows us that they he rather more 
laterally, and further that they are of a somewhat larger type than 
the vagus cells which first occur. On the same level we can also 
distinctly see accessorius roots appear, and now and then we find 
the XI nucleus, with its somewhat larger elements, present at the 
place where it can be most clearly demonstrated, viz. on the border 
of anterior and posterior horns. Although only in a few sections, it 
has been demonstrated bere tbat the XI nucleus may continue 
medially, i.e. in the direction of the central canal. My experiences 
in Camelides and in tbe giraffe have convinced me that the cells 
just mentioned, spinal from the dorsal motor vagus nucleus, though 
rather more lateral and somewhat larger, are accessoriuscells and 
that at this place another portion of the link in the original connection 
between X and XI nucleus is to be found. I shall return to this point 
later. The dorsal motor vagus nucleus is still very poorly developed, 
many sections after its appearance sometimes a few cells are to be 
seen successively in a horizontal direction, and again they are 
combined in a small group. Of these groups, which consist of 6—8 
cells, it can sometimes be demonstrated that cells of the distinet 
vagus type have left their place and have shifted in a ventro- 
lateral direction. During the development of the nucleus it remains ~ 
at first above the groove-like central canal, sometimes distinct 
commissura cells occur here, so that in this animal, though less 
developed than in Camelides and even less than in Camelopardalus 
