120 FLOllENCE R. SABIN 



those from the cup-shaped nucleus reaching all the thalamic 

 nuclei except the anterior nucleus, those from the center median 

 of Luj^s, reaching all except the anterior and medial nuclei. If 

 these conclusions are correct, we may say that at birth, only the 

 afferent fibres of these two nuclei are medullated and these af- 

 ferent fibres come from the medial lemniscus, the inferior colli- 

 culis and possibly the red nucleus. There are no other medullated 

 bundles associated with these nuclei at birth. 



The rest of the fibre mass (no, 17), which emerges from the red 

 nucleus is likewise a composite mass. It lies farther ventral and 

 more medial than BaTh and corresponds to Forel's Feld H. 

 It is a mass of fibres, oval in cross section (see Forel's fig. 11, 

 plate 7), and made up of two parts, as can be seen in fig. 4, a 

 lateral part (no. 18), Forel's Hi, which appears to be a direct con- 

 tinuation of the medial lemniscus, and a medial part (no. 19), 

 Forel's H2 which appears to emerge from the red nucleus, as can 

 be best seen in figs. 1 and 3 of the model and in section in fig 6. 

 The lateral part (no. 18), divides into a forked bundle which 

 enters the ventro-lateral nucleus of the thalamus. The more 

 ventral bundle of the fork enters the external medullated lamina 

 of the thalamus, as can be seen in the section of the adult brain 

 in fig. 8. In the different figures the number is placed at the fork 

 of the Y or on one or both branches. This is an exceedingly im 

 portant bundle since it is a part of the main cortical path, which 

 is now generally thought to consist of these three elements, the 

 posterior columns, the medial lemniscus, and the thalamo-cortical 

 radiation. In the model it will be readily seen that the ending of 

 the main lemniscus bundle in the thalamus agrees with von 

 Monkow's^ description that the lemniscus ends in the caudal 

 ventral part of the great lateral nucleus of the thalamus. This 

 ending of the lemniscus has been confirmed by Mott," more re- 

 cently by Ramon y Cajal, quoted from Sachs, and by Sachs.' 

 Sachs speaks of the ending of the lemniscus as in the "ventral 

 third and lower (i.e., caudal) half of the middle third of the lateral 



5 von Monakovv. Gehirnpathologie; Nothnagel, Specielle Pathologie und 

 Therapie, Wien. Zweite Auflage, 1905, S. 90-91. 

 « Mott, Brain, 1895. 

 ^ Sachs, il)i(l., page 130. 



