420 Heterotopia of the White Matter in the Medulla Oblongata 



different from these. In Kronthal's case the fibres formed two well- 

 defined bundles which appeared in the centre of the left nucleus nervi 

 hypoglossi and after uniting to form a single cord lay near the raphe 

 and not far from the floor of the ventricle. The fibres ended in a group 

 of large cells, probably the nucleus centralis inferior. Van Gieson's 

 is very briefly described as two bundles lying at the inner margin of 

 the nucleus nervi hypoglossi. They were supposed to be either stray 

 fibres from the fasciculus longitudinalis posterior or else association 

 fibres from the cells of the nucleus nervi hypoglossi. 



Heard reports three instances of heterotopia of the white matter, 

 two of them being found in the same medulla. The first one, he thinks, 

 corresponds to Pick's bundle, beginning at the lower end of the decussa- 

 tion of the pyramids, forming a distinct bundle which lay anterior and 

 mesial to the substantia gelatinosa, and terminating above the upper 

 end of the olives. The exact destination of this bundle could not be 

 made out: perhaps, as in Pick's cases, it ended in the corpus restiforme, 

 but more probably it passed up within the tegmentum. Heard's third 

 bundle began in the same way as his first but could be traced much 

 farther up. It lay at first midway between the tractus spinalis trigemini 

 and the fasciculus solitarius, then between the nucleus nervi facialis 

 and the second part of the root of this nerve, and was finally lost high 

 up in the pons. Just where it ended could not be made out, but cer- 

 tainly not in the corpus restiforme. The second bundle described by 

 Heard was found in the same medulla as his first one; it began higher 

 up than the former two at about the level of the exit of the eighth 

 nerve. Numbers of small fasciculi lay near the floor of the fourth 

 ventricle on either side of the mid-line, just mesial to the nuclei funic- 

 uli teretis, both of which were greatly enlarged and sent fibres into 

 the anomalous bundles. At the level of the nucleus nervi abducentis 

 'the fibres were gathered into one bundle which lay now a little to one 

 side of the median line. Farther up the bundle occupied a position 

 between the two fasciculi longitudinales posteriores and terminated 

 in the nucleus centralis superior which, on this side, was much enlarged. 



Obersteiner speaks of aji aberrant bundle which was found by one 

 of his students but not published. This is probably the one in the 

 possession of Dr. Goodkind of this city, who was at this time working 

 in Obersteiners laboratory, and who courteously gave me the specimen 

 to examine. The bimdle in this instance is the same as that described 

 as Pick's. 



The last case reported is the most interesting, as it explains the real 

 significance of most of the others, of all, that is, which correspond to 



