CIRCULATION IN THE ENCEPHALON. 105 



it j 1 and, in this opinion, Haller, Adelon, 2 and others, 3 concur ; but this 

 is not probable, and it has not been by any means demonstrated. 4 The 

 medullary portion has the appearance of being fibrous ; and it has been 

 so regarded by Leeuenhoek, 5 Vieussens, Steno, and by Gall and Spur- 

 zheim. 6 Malpighi 7 believed the gray cortical substance to be an assem- 

 blage of small follicles, intended to secrete the nervous fluid ; and the 

 white medullary substance to be composed of the excretory vessels of 

 these follicles ; and an analogous view is entertained by most physiolo- 

 gists of the present day, the gray matter at least being regarded as 

 the generator of the nervous influence ; the white matter as chiefly 

 concerned in its conduction. Gall and Spurzheim conjecture, that the 

 use of the gray matter is to be the source or nourisher of the white 

 fibres. The facts, on which they support their view, are, that the nerves 

 appear to be enlarged when they pass through a mass of gray matter, 

 and that masses of this substance are deposited in all parts of the spinal 

 cord where it sends out nerves ; but, Tiedemann 8 has remarked, that 

 in the foetus the medullary is developed before the cortical portion, and 

 he conceives the use of the latter to be to convey arterial blood, which 

 may be needed by the medullary portion for the due execution of its 

 functions. After all, however, it must be admitted with Dr. Allen 

 Thomson, 9 that the general conclusion deducible from all the facts would 

 seem to be, that whilst the gray fibres predominate in the organic or 

 sympathetic nerves, and the tubular fibres in the cerebro-spinal nerves, 

 these two elements are mixed, in various proportions, in the great divi- 

 sions of the nervous system ; and that, therefore, these divisions, al- 

 though, in a great measure, structurally different, are not altogether 

 distinct from, or independent of, each other. "But" he properly 

 adds " in regard to the whole subject of the structure and nature of 

 the different varieties of the nervous texture, it is unquestionable that 

 much still remains to be ascertained by laborious investigation." 



Sir Charles Bell 10 affirms, that he has found, at different times, all 

 the internal parts of the brain diseased, without loss of sense ; but he 

 has never seen disease general on the surface of the hemispheres without 

 derangement or oppression of mind during the patient's life ; and hence 

 he concludes, that the vesicular matter of the brain is the seat of the 

 intellect, and the tubular of the subservient parts. 11 A similar use has 

 been ascribed to the vesicular portion, from pathological observations, 

 by MM. Foville and Pinel Grandchamp. 12 This view would afford con- 

 siderable support to the opinions of Gall, Spurzheim, and others, who 

 consider the organs of the cerebral faculties to be constituted of ex- 



I Oper. Amstel., 1727. 3 Pbysiologie de 1'Homme, 2de edit., i. 208, Paris, 1829. 

 3 Carpenter, Human Physiology, p. 81,Lond., 1842. 



< Todd, Cyclop, of Anat. and Physiol., Pt. xxv. p. 647, Lond., 1844. 

 6 Philos. Transact., 1677, p. 899. 



6 Recherches sur le Systeme Nerveux en general, et sur celui du Cerveau en particulier, 

 avec figures, Paris, 1809. 



' Oper. Malpighii, and Mangeti Bibl. Anat., i. 321. 



8 Anatomic und Bildungsgeschichte des Gehirns, mit Tafeln, Niirnberg, 1816. 



9 Outlines of Physiology, Pt. i. p. 155, Edinb., 1848. 



10 Anatomy and Physiology, 5th American edit., by J. D. Godman,p. 29, New York, 1827. 



II See two interesting pathological cases, confirming this view of the function of the gray 

 matter, by Dr. Cowan, in Provincial Medical and Surgical Journal, April 16, 1845. 



13 Sur le Systeme Nerveux, Paris, 1820. 



