Anatomy of the Brain

[The brain], in humans, is spherical; whence in these its base is parallel to the horizon, [whereas] in those [quadrupeds] it cuts the horizon at a right angle, 80. It concerns the dura meninx, the cranium, and the ἐγκέφαλον (brain), 81. Its vessels are the arteries and sinuses, or receptacles, or venous channels, 82. The use of these is to receive blood and conduct it toward the heart, 83. The sinuses supply heat, as if from a water bath, required for the distillation of the spirits, 84. This membrane is endowed with motion and sensation, 85. It seems that the fibers and ligamentous chords found in the cavities of the sinuses either restrain or check the motion of the blood, 86, 87. All the uses of the dura meninx are reviewed, 88.

Chap. VII. Concerning the thinner meninx, or pia mater, concerning its extension, and also concerning the plexuses of vessels interwoven everywhere with it. P. 89

The pia meninx, internally investing all parts of the ἐγκέφαλον, separates them, 91. It supports the same blood vessels, and extends them to all parts, ibid. Its vessels, namely arteries and veins, meet one another, 92. The arteries anastomose with the arteries, 93. For which purposes it is thus established, 94. From which arteries, if three are obstructed, blood may be carried by a single approach to all parts, ibid. An Anatomical Observation, where, when the carotid artery had become osseous and was obstructed, the vertebral [artery] had become larger than usual, 95. The arteries, encountering the veins everywhere, constitute admirable plexuses,