8 Edward F. }[alone. 



since the homologous groups in various mammals are so constant both 

 as to location, extent and cell character, it appears highly probable that 

 we shall not have to wait long before this name may be abandoned for 

 one which will indicate its true function, and until then it seems better 

 not to introduce a temporary name implying merely some morpholog- 

 ical character. In arriving at the function of a cell group the first 

 essential (and probably the most important of all) is to clearly dis- 

 tinguish it from the surrounding cell groups and to study carefully 

 its relations to such cell groups ; in this article I shall endeavor by 

 means of illustrations and description to make the resulting picture 

 of the so-called basal optic ganglion so definite that its confusion with 

 all other cell groups will be impossible, and if this result be obtained 

 there need be little concern as to the fitness of the name employed. 



Location and extent of the ganglion opticuni basale. 



MAX. 



The basal optic ganglion in man is a mass of gray matter, super- 

 ficially situated partly in the tuber cinereum and partly in the anterior 

 perforated substance, which extends along both borders of the optic 

 tract. The main mass of cells forms in the anterior j>erforated 

 substance a column which is closely applied to the dorsal portion of the 

 oro-lateral surface of the optic tract. This mass is connected by a 

 comparatively small number of scattered cells situated directly dorsal 

 to the tract with another cell mass which follows in the tuber cinereum 

 the caudo-medial border of the optic tract ; in other words the basal optic 

 ganglion consists, generally speaking, of two parallel columns of cells 

 lying along either side of the optic tract, which are connected by 

 scattered cells of the same type lying dorsal to the optic tract. For the 

 second time I strongly recommend a consideration of pp. 39-40, where 

 it is pointed out just what each type of illustration is intended to show. 



Taking up the first series of man (Series AC) the basal optic gang- 

 lion appears caudally in Fig. 4 as a few scattered cells situated on the 

 peripher}- of the tuber cinereum ; Figs. 5 and 6 show the development 

 of the cell mass as we pass orally. The cell masses shown in Figs. 4 

 and 5 are to be regarded as a caudal projection of the cell column lying 

 along the caudo-medial border of the optic tract, and are continuous 

 with the caudal portion of this cell column which appears first in Fig. 6. 

 Between Figs. 6 and 7 is a considerable gap, in which the following 



