Holm ') on this subject in J 902, which is certainly the best de- 

 scription as jet given of the motor nuclei in Myxine ^lutinosa. 



Holm points out that tlie motor column of the spinal cord (comp. 

 our Fig. 10) can be traced fron tally in the bulb. 



Laterally from it lies the posterior extremity of what Sandehs has 

 called the lateral or latero-ventral cell group (comp. our. Fig. 9). 



Holm divides this latero-central column of the bulb, which we 

 shall call the viscero-motor column, into two divisions, a frontal and 

 a caudal one. 



He again divides the frontal division into two, the caudal one 

 into three subdivisions. 



We can on\y follow him in so far as we also divide the viscero- 

 motor column into two divisions (see Fig. 2 and Fig. 3) of which 

 howevei- only the frontal one is again divided into two subdivisions. 

 The caudal viscero-motor division, in our opinion, is continuous (see 

 Fig. 2 and 3 nucl. X mot.) and does not exhibit subdivisions. 



Apart from this column Holm mentions a group of cells located 

 next the ventricle in the rosti-al part of the oblongata from which 

 he thinks that a part of the motor trigeminus originates. Another 

 part of the motor trigeminus should originate from a nucleus in the 

 lateral part of the oblongata on the level of the acusticus ganglion. 



The nuclei of the trigeminus thus would be located at a fairly 

 great distance from each other, one lying neai- the ventricle, the other 

 near the perifery of the bulb. (Comp. his Fig. 20 on Plate 21 : 

 Nc I m. N V and Nc II m. N V). 



We do no agree with this description, nor with his statements 

 concerning the motor facialis. 



Also the facialis — according to Holm's opinion — should have two 

 nuclei (1. c. p. 389) and from his descrij)tion it clearly appears that 

 he considers our frontal motor V nucleus as a VII nucleus, ibi- the 

 axones of this nucleus — as shown in his drawings — (Fig. 21 

 Plate 21) constitute the most frontal root of the bulb. 



No doubt the two VII roots described by Holm {Vila and VI 16) 

 are V roots, since only this nerve leaves the bulb with two motor 

 roots ^), whereas the motor VII root is single and veiy small. ()ur 

 opinion is confirmed by his description of the corresponding nuclei. 



The first VII nucleus described by this author lies in the frontal 

 part of the bulb near the perifery, and consists of large cells. His 



1) J. F. Holm. The finer Anatomy of the nervous system of Myxine glutinosa. 

 Morpholog. Jahrbiiph Bnd. 29, 1902. 



-) This separation of the motor V in two roots is only visible near the en- 

 trance. Soon after it they unite. 



