viii Journal of Comparative Neurology. 



other intra-cellular. The former is regarded as a reticukim of origin, 

 not of termination, the individual fibres apparently arising within the 

 cell and uniting to form the spiral fibres, which is considered to be a 

 cellifugal prolongation of the subjacent ganglion cell. On the other 

 hand the intra-cellular reticulum is composed of filaments of the same 

 optical properties as those which go to make up the greater process of 

 the ganglion cell and the author suggests that they are the cellipetal fibres 

 which on entering the cell body spread through it and form an intra- 

 cellular superficial reticulum which in some way is to come into phys- 

 iological relations with the extra-cellular cellifugal reticulum. We shall 

 await with interest a more full description and confirmation of the pre- 

 liminary account of relations which are certainly sufficiently remark- 

 able to justify a litde hesitation in giving them an unqualified accept- 

 ance without the most rigorous proofs. 



c. J. H. 



Structure of the Thalamus.^ 



Corpus Luysii, or nidus hypothalamicus of man. This receives 

 fibres from the tractus opticus, which come chiefly from Meynert's com- 

 missure. Apparently Gudden's commissure also sends fibres into the 

 nidus hypothalamicus. The latter receives other fibres from the lenti- 

 cular nidus which penetrate it from the lateral aspect and also from the 

 tegmental bundle of the caudatum. Finally there is to be mentioned 

 a commissure of the nidi hypothalamici on the dorsal side of the most 

 caudal portion of the mammillaria. 



Opticus termini. In the mouse, termini of the opticus fibres were 

 found in the corpus geniculatum laterale, in the thalamus itself and in 

 the corpus quadrigeminum anterius. In the two first mentioned the 

 termini are like those described for the lobi optici of birds, that is, with 

 much branched, compact terminal tufts which lie pardy in the interior 

 of the corpora geniculata lateralia and of the thalamus and partly in the 

 stratum zonale of the latter. In the corpus quadrigeminum anterius, 

 on the other hand, no such tufts were found but endings loosely 

 branched over a larger area, which spread from the second white layer 

 especially into the outer grey zone. In young rabbits were found in 

 the layer of the tractus opticus laterally of the thalamus large cells 

 which send their nervous processes centrifu gaily into the tractus. It 

 was impossible to determine whether these fibres pass to Gudden's com- 



* KOELLIKER, A. V. Zum feineren Baue des Zwischenhirns und der Regio 

 hypothalmica. Verh. Anat. Ges., IX Vers., 1895. 



