306 



The malerial examined for lliis study has been fixed in ale. 950/o and is embed- 

 ded in parafOnc. Tiie slem of Equus, Bos, Gapra and Ganis familiaris lias been 

 slained with lokiidine biue, that of Sus scrofa dom. with cresyl-violelte. 



Equus cahallus. Tlie dorsal motor nucleus of tbe X^'' extends over 

 520 sections of 18 fi. Tiie calamus is found in section 214, counted 

 in caudo-frontal direction. Consequently Vs o^ tiie nucleus is found 

 in the closed part of the oblongata (see fig. 2) and Vb ^^ the. open 

 part of it. In the closed part it is first a small group of cells, 

 growing considerably in frontal direction. 



Tiie lateral part, which increases most, conlains several large cells. 



In consequence of the suiall size of Ihe XII nucleus on this level 

 the cells of the motor X come nearer to the central canal than those 

 of the XIP'' . More frontally the XII''* nucleus enlarges and the cells 

 of the X'^'i then are entirely doi'sally and later dorso-laterally from it 

 In tiie middle of its length the dorsal ^'agus nucleus has acquired 

 its greatest size. It then has a pyramidal foi'm, the top of the 

 pyramid being directed towards the ventricle. One section may show 

 80 — 100 cells. More frontally the top of the pyramid disap[)ears 

 so that the rest of the nucleus is entirely situated laterally to the 

 XII^i', on a somewhat dee])er level. 



In this series the dorsal vagus nucleus is found to extend still 

 28 sections more frontally than the caudal limit of the facial nucleus. 

 Equus. Bos taums 



Caud. 



Canis familiaris 

 I 



Front 



■j-.- •. . . XII 



r 



Fig. 3. 



Section through the dorsal motor X'*^ 

 and the XII''' nucleus of Equus caballus. 



Fig. 2. 



Extension of the nucleus motorius dorsalis 



vagi (black) in regard to the Calamus 



scriplorius (doited line). 



