154 



may enlarge medially in such animals (as Ornithorrhynclius) where the fibres that 

 may be called capsula interna fibres, take a more medial course than usually. 

 Moreover we know that frontally, where the capsula interna fails, the putamen and 

 caudate nucleus fuse and that this fusion is larger the smaller the frontal extension 

 of the capsula is. (E. de Vries) ')■ Such a fusion may also occur caudally (f. i. in 

 Elephas). 



Also Hie separation of the palaeostriatum and neostriatum bj the 

 lamina medullaris externa is very evident in man (as also tlie 

 lamina medullaris iutei'na). 



NS'' 



Fig. 19. Neostriatum (iV.S and iVS'), archistriatum or amygdala (/I. S.) 

 and palaeostriatum (P. S.). V. S. = large bloodvessel in 

 the lamina medull. externa. Laterally from the neostriatum 

 (N. S.) the claustrum is seen. 



At last 1 want to call the attention to tlie fact that in the normal 

 human cerebrum the lam. medullaris externa — as in birds — 

 is a place of predilection of bloodvessels more than the other 

 (internal) lamina (vide fig. 19). 



Also the connections of the avian striatum (which we know chiefly through 

 the works of Boyce and Warrington, Edinger, Wallenberg, and Holmeü and 



1) E. DE Vries. Das Corpus Striatum der Saugetiere. Anat. Anzeiger, Bnd. 37, 1910. 



