. Quain's elements of anatomy . inefissure, the line of Vicq dAzyr is very distinct but the inner liae of BaiUargeris not visible (fig. 308, 2). This grey substance of the convolutions contains cells and fibres STEUCTUEE OF THE GEEY MATTEE. 357 embedded in neuroglia,with mimerous blood-vessels, which pass verticallyinwards at the surface but in the deeper parts are more irregularlydisposed. The cells are of various forms and sizes, many of them with numerousprocesses. Some of these branching cells are irregular in form and posi-tion, but the majority are more regularly pyiamidal in shape, with
. Quain's elements of anatomy . inefissure, the line of Vicq dAzyr is very distinct but the inner liae of BaiUargeris not visible (fig. 308, 2). This grey substance of the convolutions contains cells and fibres STEUCTUEE OF THE GEEY MATTEE. 357 embedded in neuroglia,with mimerous blood-vessels, which pass verticallyinwards at the surface but in the deeper parts are more irregularlydisposed. The cells are of various forms and sizes, many of them with numerousprocesses. Some of these branching cells are irregular in form and posi-tion, but the majority are more regularly pyiamidal in shape, with theapex of the pyramid turned towards the surface of the convolution. Theaverage size of the larger pyramidal cells is tsVo*^-^ of an inch in dia-meter at the base, and each has a rounded nucleus having an averagediameter of ^-^00^^ of an inch. They generally contain a little yellowishpigment. The cells often appear to lie in distinct cavities in the gTeymatter (pericellular spaces), but it is uncertain if these are natural or. Fig. 308.—Sections op cerebral con-volutions (after Baillarger). Tlie parts are neai-ly of the natural , shows the six layers ordinarily seenin the cerebral cortex when carefullyexamined with the naked eye ; 2, theappearance of a section of a convolutionfrom the neighboui-hood of the calcarinefissure. produced by shrinking after death. The process from the apex of eachcell may be traced for some distance towards the surface of the con-volution giving off one or two branches as it passes outwards. Themode of termination of these branches is unknown. Several finebranching processes pass from the angles at the base of the cell andrun outwards or towards the medullary centre. Some of these pro-cesses divide and ramify, the branches forming a network of fine anasto-mosing fibres, while others have been traced inwards undivided, andone process at least from each cell is probably continuous with the axis-cylinder of a nerve-fibre. The undivided axis-cy
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