nucleus (nucleus intermedius?) The whole tongue nucleus has 
now become triangular, with the base towards the ependyma; 
the ventral pole then contains the smallest cells, except for a 
few lying medially which have distinctly kept the anterior horn type. 
We now see repeatedly a clear division into 3 groups, a medio- 
dorsal, a latero-dorsal and a ventral group; the whole may contain 
as many as 80 cells. The cells between tongue and vagus nucleus 
are often so numerous that they quite connect the two nuclei. 
Further frontally the whole diminishes owing to all the groups 
becoming looser in construction; the bridge which had meanwhile 
disappeared between the ventral pole of XII and the vagus nucleus 
again makes its appearance, though im a less degree, and soon 
the tongue nucleus arranges itself in several small groups, 4, 5 and 
occasionally even 6 separate groups appearing. In the same region 
the connecting link between XII and X dorsalis is again complete 
(fig. 6). Now the ventral portion disappears, and we see the rest of 
the nucleus divide again into a medial and a lateral portion, the 
lateral portion with large cells and the most strongly developed. 
Then the medial portion disappears, and finally the lateral. When 
the medial has disappeared, a few cells of the ventral pole again 
make their appearance in some sections. 
Nucleus accessor. It is a very remarkable feature in Phocaena that 
the accessorius nucleus can be traced frontally to within a few sections 
spinally from the calamus. There it can be seen, though very poorly 
developed, with usually no more than 2 or 3 cells, at the place 
most clearly to be defined, viz. on the lateral border of anterior 
and posterior horns. Its efferent roots follow the much curved 
posterior edge of the posterior horn. In some sections, in which 
nucleus XI is present, the direct connection with the nucleus moto- 
rius X dorsalis can be observed. This takes place with but a few 
cells and can also be demonstrated repeatedly in more spinal regioas 
(fig. 8). There we can frequently see the XI nucleus also at the 
above-mentioned place and likewise how it spreads in ventro-lateral 
direction, along the dorso-lateral edge of the anterior horn. At other 
places, on the contrary, it spreads along the lower edge of the 
posterior horn, and contains then 8—10 cells of a fairly small type. 
Frequently we see ventro-laterally from the posterior horn a separate 
cell group of the XI nucleus with 8—10 cells, and also radiations 
of it in the direction of the medial group at the well-known place. 
The efferent XI root runs beneath the former group. Here, too, 
connecting cells are to be seen from the medial greup to X. dorsalis 
