Anatomy, descriptive and surgical / by Henry Gray ; teh drawings by H.V. Carter ; with additional drawings in the second and later editions by Dr. Westmacott ; the dissections jointly by the author and Dr. Carter ; with an introd. on general anatomy and development, by T. Holmes.
- Henry Gray
- Date:
- [1877]
Licence: Public Domain Mark
Credit: Anatomy, descriptive and surgical / by Henry Gray ; teh drawings by H.V. Carter ; with additional drawings in the second and later editions by Dr. Westmacott ; the dissections jointly by the author and Dr. Carter ; with an introd. on general anatomy and development, by T. Holmes. Source: Wellcome Collection.
Provider: This material has been provided by the Francis A. Countway Library of Medicine, through the Medical Heritage Library. The original may be consulted at the Francis A. Countway Library of Medicine, Harvard Medical School.
74/974
![Tey. White. 5-2 73-0 7-5 9-9 ro 13-9 37 0-9 I'4 i-o 1-2 1-3 Ixxii GE]!^ERAL ANATOMY. spiual (see especially the description of tlie olfactory nerve, inft-a, p. 501), consist of a fourth description of nervous fibres*, which are called the grey or ^eZaimoits nerve-fibres (fibres of Eemak). (Pig. XXXIII.) These consist of a bundle of finely-granular fibrillffi enclosed in a sheath. Nuclei may be detected at intei'vals in each fibre, which Schultze believes to be situated in the sheath of the nerve. In external appearance the gelatinous nerves are semi-transparent, and grey or yellowish-grey. The individual fibres vary in size—most of them being of smaller size than in the cerebro-spinal nerves, so that the average size of the latter is given at ^j-gVo *° 30^00 '^^ an inch, and of the former at only half that size; but, on the one hand, the smallest fibrils of the cerebro-spinal system are, as we have seen, of hardly appreciable thickness ; while, on the other, some of the gelatinous fibres (especially those in the olfactory bulb) are said to be three or four times as thick as those of the cerebro-spinal nerves. Gliemical composition.—The following analysis, by Lassaigne, represents the relative proportion of the different constituents composing the grey and white matter of the brain :— Water 85 Albuminous matter Colourless fat Red fat Osmazome aud lactates . . . . Phosphates ....... It appears from this analysis that the cerebral substance consists of albumen, dissolved in water, combined with fatty matters and salts. The fatty matters, according to Fremy, consist of cerebric acid, which is most abundant, cholesterin, oleophosphoric acid, and olein, margarin, and traces of their acids. The same analyst states that the fat contained in the brain is confined almost exclusively to the white substance, and that its colour becomes lost when the fatty matters are removed. According to Yauquelin, the cord contains a larger proportion of fat than the brain; and, according to L'Heritier, the nerves contain more albumen and more soft fat than the brain. With regard to the constitution of the different portions of the nervous system, the cerebro-spinal axis is composed of the two above-described kinds of nervous structure, intermingled in various proportions, and having in the brain a very intricate arrangement, which can only be fully understood by a careful study of the details of its descriptive anatomy in the sequel. The grey or vesicular nervous matter is found partly on the surface of the brain, forming the convolutions of the cerebrum, which are in the most direct relation to the mental faculties, and the laminee of the cerebellum, the functions of which are still a matter of dispute. Again, gi-ey matter is found in the interior of the brain, collected into large and distinct masses or ganglionic bodies, such as the corpus striatum, optic thalamus, and corpora quadrigemina; the functions of which bodies, so far as they have been ascertained, have been found to be connected with some * The real nature of these fibres has been doubted by several authors. It seems better, however, and more consonant with the prevalent opinion, to describe them as truly nervous.](https://iiif.wellcomecollection.org/image/b21055087_0074.jp2/full/800%2C/0/default.jpg)
