307 



Bos taurus. 



The dorsal niolor iiiicleiiH of llic X'-' covers 500 secliojis ot 18 fi. 

 The caliuiiiis is IoiiikI in seclioii 212, coimled IVom (ho caiuUil pole 

 of the micleus, so that, similarly as in the horse, 7^ of it are found 

 in the closed part (caudally from the calamus) and 7^ in front of 

 it (comp. fig. 2). 



It begins as a small grou}) of cells, candally from the hind pole 

 of the XIP'' . It soon increases in size and 

 is already a considerable mass of cells when 

 the Xlph ijucleus appears in the sections, 



lying dorso-laterally from the latter. Already ( . f.'' ',';•<■'•''.'• " ^ 



here the nucleus is mnch larger than in the 

 horse. Forty sections behind the calamus 

 the X^'^ nucleus is twice as large as on the 

 corresponding place in the hoi'se. 



Near the calamus the nucleus has acquired 



a considerable dorso-medial extension growing ' "^^'^\ t ' ,^ ^^^ 



towards the floor of the ventricle. Soon after ' ' ■■ • r i^v 



that it acquires also a pyramidal form, the Fig. 4. 



top of the pyraniid being directed towards Section through the 

 ,1 i • 1 't .• i^rxr^ II dorsal motor X^'^ nucleus 



the ventricle. In one section 200 cells were and the Xll'i^ nucleus of Bos 



found. As a rule the cells are larger than taurus. 



in the horse and the number of the large type of cells has obviously 



increased, several of them exhibiting the large motor type (comp. 



fig. 3 and 4). The nucleus still increases gradually in size beyond 



the calamus and keeps its maximum of development as far as the frontal 



third of its extension, in which it gradually decreases again, first 



losing the top. It is however still a considerable nucleus when the 



XII has already disappeared. '). 



In my series the vagus nucleus extends 75 sections in front of 



the hind pole of the VII''', thus exhibidng in every respect a greater 



size than in the horse. 



Capra hircus. The dorsal motor nucleus covers a series of 290 

 sections of 15 fx. The calamus is found in section 185 counted from 

 the caudal limit of nucleus. Consequently the relation between the 

 parts contained in the closed region of the oblongata aiid that in 

 the open bulb is reversed, 75 of it occurring in the spinal oblongata, 

 75 in the open region (see fig. 2). The nucleus begins 60 sections 

 behind the caudal pole of the Xll''' as a small groiq) of cells lying 



1) The nucleus Xll of the cow seems to be less developed though than in liorse. 



20* 



