THE 
VETERINARIAN. 
VOL. VI, No. 69.] SEPTEMBER,' 1833. [New Series, No. 9 . 
MR. YOUATT’S VETERINARY LECTURES, 
DELIVERED AT THE UNIVERSITY OF LONDON. 
The bones of the cranium in most of our domesticated animals 
having been described at pp. 191 and 265 of the fourth volume 
of The Veterinarian, v^e proceed to 
LECTURE XXXV. 
The Membranes of the Brain—The Size, Form, and Composition 
of the Brain—The F mictions of the Cineritious and Medullary 
Portions, and the Intellectual Principle in Animals. 
The Dura Mater in the Horse. — On endeavouring to raise the 
roof of the skull in any of our patients, we find, adhering to the 
inner surface of the bone, and separated from it with difficulty, 
a dense and strong membrane, the dura mater, at once the inter¬ 
nal periosteum of the bone, and the covering of the brain. It 
adheres to the bone by innumerable prolongations of its sub¬ 
stance, and by minute vessels ; and these are most plentiful along 
the sutures, and the ridges of the bones. If I macerate either 
of the bones composing the cranium in diluted muriatic acid, 
the earthy matter will be dissolved, and I shall have remaining 
the, outer and the inner membrane—the pericranium and the 
internal periosteum—with a great deal of interposed cellular tis¬ 
sue, and numerous vessels of communication. 
Nature of the Membrane. —This adhesion to the bone gives to 
the dura mater a roughened surface exteriorly, while it presents 
a polished, glistening face to the membranes below; thereby 
obviating injurious friction between them. The dura mater is 
united to the membranes beneath by many little cords or pro¬ 
longations of its substance, and these chiefly following the direc¬ 
tion of the sinuses. Each of these little cords or doublings 
of the membrane carries a small bloodvessel, and penetrates 
through the other membranes, and enters into the substance of 
the brain, and is firmly tied down wherever it enters, thus answer¬ 
ing the double purposes of carrying blood, and giving support to 
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