655 



and assuming the same forms as before. First a large loose group, 

 in which as many as 50 cells may be counted, and then the triangle 

 with all its derivatives, now mainly the base, again the base with 

 the lateral side or the whole triangle. Sometimes the three corners 

 are sharply defined by fine groups of cells, while here the characteristic 

 shape of the arabiguus with its dorso-medial and ventro-lateral parts 

 is also present. In the calamus there is again a decrease to 8 — 12 

 cells lying in ventro-lateral direction, while from the calamus to the 

 frontal pole of nucleus XII, the development is much less marked 

 than spinall3' from the calamus. The greatest number of cells 

 contained hei-e by the ambiguus is 18 — 20, sometimes it is altogether 

 absent. At the frontal pole of the tongue nucleus we see very 

 clearly in few sections the sinking of a few ambiguus cells into a 

 more ventral level, and very soon the huge frontal bulging makes 

 its appearance. This grows to an irregular oval form, with a maximum 

 of 110 cells, the majority being large, genuine ambiguus cells. As 

 in the lama and the camel the cells here are not crowded together 

 but lie rather scattered. Ventrally from this large group is a smaller 

 one, consisting principally of cells of a 

 much smaller type. Whether this group 

 too belongs to the arabiguus I do not 

 venture to assert (fig. 2 and 11). As 

 usual the bulging of the ambiguus begins 

 to decrease at the frontal pole of the 

 dorsal motor vagus nucleus and soon 

 ■.'"''' "I" after decreases rapidly. Ten sections before 



,''.'■'• j^' its final disappearance it has still 25 cells. 



In this animal the frontal pole of the 

 "■ ambiguus stretches 46 sections frontally 



from the dorsal motor vagus nucleus (fig. 2), and reaches over a 

 stretch of 1 2 sections the region of the nucl. facialis. The remainder 

 of the ambiguus then lies dorso-medially from the caudal pole of 

 nucl. VII. 



J^ucleus accessorii. In this series the first XI cells can be seen 

 on the border of the anterior and posterioi' horns, 1188 sections spinalh' 

 from the appearance of the nucleus motorius dorsalis vagi. These 

 increase and a group of 14 cells is soon present, of a suuiller type 

 than the large motor cells of the anterior horn. It rapidly decreases 

 in size and soon disappears altogether at this place. Cells of a similar 

 type appear however in several sections, dorso-laterally from the 

 canalis centralis, further lateral than where the dorsal motor vagus 



