6 Edward F. Malone. 



S. Nucleus tubero-mammilla/ris. 



The cells of the so-called lateral ganglion of the corpus mammillare 

 may be readily followed orally and laterally into the angle between the 

 pes pedunculi and the tractus opticus, whereas orally and dorsally they 

 may be followed through many sections accompanying the tractus 

 thalamo-mammillaris and the columna fornicis. To this complex of 

 cells having an identical histological character I gave (1910) the name 

 " nucleus mammillo-infundibularis," a name which Friedemann 

 (1911) has adopted in his article on the diencephalon of cercopithecus. 

 It is evident that this name is unsuitable, since the cell group is not 

 situated in the infundibulum, and I have therefore changed it to 

 " nucleus tubero-mammillaris." The nucleus tubero-mammillaris is 

 shown in all the series illustrated and its relation to the basal optic 

 ganglion and the nuclei tuberis may be readily seen. (Since the figures 

 were drawn and labeled before I decided to change the name of this 

 nucleus, it appears on tlie outline drawings as "• nucleus mammillo-in- 

 fundibularis," but wherever space has permitted the new name has 

 been added in parentheses. The explanation of each plate is so ar- 

 ranged as to remove any possibility of confusion.) The character of its 

 cells in the different forms is illustrated in Figs. 41, 47, 52 and 57. 

 The relation of this nucleus to the basal optic ganglion will be discussed 

 later. It should be noted that a portion of this nucleus is situated in 

 the pars optica. 



Jf. Nucleus paraveniricularis hypothalami. 



This characteristic column of cells is situated partly in the pars 

 mammillaris but principally in the pars optica. Its location is shown 

 in all the series, and the character of its cells in Figs. 43, 49, 54 and 

 58. In man this nucleus was first described by me in 1910, and the 

 fact that such a striking cell group had not been previously described 

 in man is probably due to the almost exclusive use of fiber stains. In 

 1911 Friedemann found this cell group in cercopithecus. It is certainly 

 homologous with the group described by Cajal in rodents under the 

 name of " niicleo subventricular,"' and ^^^th that described by Ziehen 

 in marsupials as " Nucleus subcommissuralis." Homologous groups 

 are also possibly found in vertebrates even as low as the fishes. The 

 nucleus paraventricularis is intimately related to the basal optic gang- 

 lion and also to the nucleus tubero-mammillaris as tliese three nuclei 



