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in contradiction to it. On the basis of his pliylogenetic and 

 embryologie studies, Kappers came to the conviction that the 

 nucleus accessorii and the ambiguus have nothing to do with the 

 spinal system, but that both are direct continuations of the dorsal 

 motor vagus nucleus; the accessorius nucleus exhibits hereby the 

 peculiarity that it grows from its cerebral oi'igin into the cervical 

 cord, sometimes along almost its entire length. My confirmation of 

 tills position of the XI nucleus and the dorsal motor vagus nucleus 

 in a calf's foetus, in ovis aries neonatus and sus sci'ofa domesticus 

 neonatus, of what Kappers found in embryos of sheep, and especially 

 tlie fact that the connection between these two nuclei is still to be 

 found in Camelidae and so clearly and repeatedly in the giraffe, 

 strengthen, in my opinion. Kappers' theory to no small extent. Other 

 difficulties, however, present themselves with regard to this question. 

 BoLK has described that also anterior horn roots leave witli tlie nervus 

 accessorius, so that what has never yet been demonstrated in any 

 other place in the animal body takes place here, viz. tliat viscero- 

 motor and somatomotor fibres unite. I have now observed that 

 in the first cervical segment of the giraiTe, cells from the anterior horn 

 join the accessorius nucleus. The question is now whether these are 

 genuine frontal horn cells or accessorius cells. Only from the first 

 cervical segment do we find frontally, the XI nucleus at the sharply 

 defined place, viz. or mainly at least, in the corner between the 

 anterior and posterior horns ; if we follow this nucleus spinally we see 

 the connection with motor cells on the dorso-lateral border of the 

 frontal horn, but later we can affirm that the XI nucleus has disappeared 

 entirely from the corner indicated, although in this and even in 

 regions lying much more caiidally the nervus accessorius may arise 

 and 'in that case its nucleus must still be present; in other words, 

 this nucleus may have sunk away in the midst of genuine frontal horn 

 cells and the derivatives of the dorsal motor vagus nucleus may 

 finally disappear in the middle of the motor elements of the grey 

 matter of the neck. There is therefore the possibility that the bundles 

 described by 'Bolk contain accessorius fibres after all, I will add, 

 however, immediately that I am willing to admit the possibility of 

 a simultaneous rise of XI and frontal horn roots, in the first place 

 because a priori the coincidence of viscero-motor and somato- 

 motor fibres must not be considered as impossible in view 

 of the fact that everywhere raotory, sensory, and autonomic fibres 

 combine, and in the second place because of the fact that in 

 Camelidae XI fibres must necessarily originate together with 

 cervical nerves. These animals have a musculus trapezius. 



