The nuclei tuberis laterales and the so-called ganglion opticum basale.

  • Malone, Edward F.
Date:
1914
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Licence: In copyright

Credit: The nuclei tuberis laterales and the so-called ganglion opticum basale. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

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    tion types, whose significance will be discussed later. The nuclei tuberis laterales must be sharply distinguished from certain regions of the substantia grisea in which the cells are more densely packed together than in other portions of the substantia grisea. Differences in the density of different portions of the substantia, grisea may be seen in many sections, and very definite areas of closely packed cells are shown in Figs. 17, 22 and 24. While in such dense masses the cells are possibly somewhat larger than the remaining cells of the substantia grisea, I do not consider the difference in cell type clear enough to justify one in setting aside such dense cell masses as distinct nuclei. Whatever the significance of these denser cell masses of the substantia, grisea, one fact is certain: they differ both in location and in cell type from the nuclei tuberis laterales; the radical difference between these two kinds of cell groups should be clearly recognized. Of course the structure of the cells of the nuclei tuberis laterales as well as that of the cells of the substantia grisea is radically different from that of motor cells, while the small size of both types of cells would indicate that the connections of each cell were very limited; this correlation between cell size and the extent of the connections of each cell has already been referred to. Eelationship Of The Various Cell Groups To One Another. From the previous description of the various cell groups together with a reference to the figures showing their cell types, it will be evident that the cell groups herein considered fall naturally into two classes: 1. Those composed of small cells, including the substantia grisea, and the nuclei tuberis laterales, and 2. Those composed of large cells, including the basal optic gang- lion, the nucleus paraventricularis hypothalami, the nucleus tubero- mammillaris, and perhaps also the nucleus ansae peduncularis (gang- lion basale). Taking up the first class of nuclei a most interesting relation will be found to exist between the substantia grisea and the nuclei tuberis laterales. The cells of the substantia grisea are the most primitive of the hypothalamus. The constancy of cell type in all four animal forms would suggest this, but the strongest evidence is derived from the nature of the cell type. The cell type of the substantia grisea, with its scanty cytoplasm, resembles that of embryonic cells; it occurs often in