300 



beliiiul the axlatnus (i>ee lig. 2). Tlic lirst cells of tlie dorsal X''' appear 

 62 sections behind the caudal limit of the Xll^'' , dorso-laterallj from 

 the central canal. When the XIP'' nucleus 

 appears the X is found dorsal ly from 

 it. Near the calamus its cells protrude 

 only a little laterally from the XII, wliicli 

 on this level has already required a 

 considerable size. Only in the open bulb 



the increase of the nucleus becomes more >/ .*.. ^' ■ ■ x 



developed, showing a similar form as in 



the pig: a pyramid, the base of which y^ :_\- ^:\,-'- xil 



lies near the floor of the fourth ventricle. 

 Approaching more and more the epen- 



dyma, the largest number ofits cells is ^, . ,^^o- ?' , , , 

 •^ Section through the dorsal 



found to be 80. Ihe large type of eel Is motor X nucleus ana the XII 

 is however — similarly as in the horse — "ücleus of Ganis familiaris. 

 much less frequent than in the runjinantia and in the pig. The 

 nucleus has its greatest size on a more frontal level than in other 

 animals. Over several sections the nucleus keeps a considerable size 

 and then livst decreases at its dorsal border, while the rest of it 

 remains on a lower level, lying laterally not dorso-laterally from the 

 XII. The most frontal part as in the othei- animals extends a little 

 beyond the caudal limit of the facial nucleus as has also been 

 described by Kappers ^). 



From the foregoing pages appears that, in our domestic animals, 

 the dorsal motor nucleus of the X''' has the least development in 

 the horse, in which also the cells of large type are less numerous. 

 The anatomical characteristics of oesophagus and stomach seem to 

 be in accordance with this. Kosaka ^) has demonstrated that the 

 dorsal vagal nucleus innervates the posterior part of the oesophagus, 

 the stomach and the lungs, [n the horse the cervical part of the 

 oesophagus contains striped musculature, the thoracic part and stomach 

 smooth musculature. Only microscopically vestiges of striped mus- 

 culature can be traced in the latter"'). In this animal the size of the 

 ventricle is relatively small and consequently there is not much 

 smooth musculature and glands. In the cow, sheep, goat, pig, and dog this 



1) G. U. Ariëns Kappers. Weitere Milteilungen über Neurobiotaxis, VIL Die 

 pliylogenetische Enlwicklung dor motorischen Kei'ne in Oblongata und Miilelhirn, 

 Foiia Neurobiologica, Ergiinz. Heft. Bnd VI 1912. S. 116. Fig. 102. 



~) Kosaka. Ueber die Vagnskei'ne des Hundes. Neurologisches Gentralblatt 

 No. 8. 1909. S. 4 u. 5. 



^) Ellenberger. Handbuch dor vergleichenden Mikroskopischen Anatomie der 

 Haustiere. 



