974 
(fig. 8). As usual the XI nucleus disappears and reappears periodic- 
ally. In this region several sharply outlined longitudinally running 
bundles have appeared in the middle-horn and also ventrally from 
it. These are stronger in a spinal direction, and in some of the 
sections have driven the medial group of XI cells, on the border of 
anterior and posterior horns, somewhat upwards, i.e. in the direction 
of the lateral group of XI cells, lying near the latero-caudal edge 
of the posterior horn. Since, further spinally behind the spinal pole 
of X dorsalis, the posterior horn turns much upwards, the lateral 
Fig. S. Phocaena communis. Fig. 9. Phocaena communis. 
group of the accessorius nucleus diverges more and more from the 
medial group, and as the efferent XI roots continue to follow the 
posterior horn, we see these in this level arise in a region lying 
more dorsally than frontally (fig. 9). 
Of the XI nucleus of Phocaena cells are thus to be observed: 
a. On the border of anterior and posterior horns, 
Db. medially, in the direction of, and in connection with X dorsalis, 
ce. ventrally from it, along the dorso-lateral edge of the anterior horn, 
