THE NERVOUS SYSTEM. \SB 



grey, and at the same time less firm to the feel, as the 

 a. caroticus intermix, the nn. carotid exterm .°. molles, the ////. 

 cardiaci, the vascular branches in general, the branches con- 

 necting the large ganglia and plexuses in the abdomen, those 

 which euter the glands, and the pelvic plexuses. The peculiar 

 condition of the latter nerves depends, in part, upon the paler 

 colour of the fine fibres of the sympathetic itself, but in 

 great measure upon the presence of the fibres, named a 

 their discoverer, the fibres of Remak ("gelatinous fibres" of 

 Henle), which were at first regarded as a kind of nerve-tubes, 

 and of which, even now, some cannot be convinced that they 

 are only a sort of connective tissue. They are sometimes more 

 readily isolated, sometimes more united into a compact sub- 

 stance resembling homogeneous connective tissue. In the 

 former case they present the aspect of flat, pale fibres, 0-0015 

 — 0-002.V" broad and 0-0006'" thick, of an indistinctly 

 striated, granular, or more homogeneous substance ; and which, 

 under the action of dilute organic acids, exhibit precisely 

 the same conditions as connective tissue, and from point to 

 point are furnished with, mostly elongated, or fusiform nuclei, 

 0-003 — 0-007'" long, 00'2 — 0-003'" broad. These fibres, 

 again, are found in almost all the grey portions of the ganglionic 

 nerves — I cannot find them in many parts of the pelvic plexuses 

 in Man, where they are replaced by a non-nucleated abundant 

 connective tissue, though they are said by Remak to abound 

 in the nerves of the impregnated uterus, ( f Darmnerveusyst./ 

 p. 30) in very great quantity, so that they amount to from 

 three to ten times the number of the dark-bordered true 

 nerve-fibres. They constitute the main part of the proper 

 basis of these trunks, and the dark-bordered tubes extend 

 through them, sometimes more isolated, sometimes assembled 

 in larger or smaller fasciculi ; more rarely, and only in the 

 neighbourhood of the ganglia themselves, do they appear to 

 form sheaths to individual tubes of the finest kind. Besides 

 these ' fibres of Remak/ the peripheral ramifications of the 

 sympathetic are, above all, distinguished by a great number of 

 ganglia. These bodies, of a larger or less size, some even 

 microscopic, are placed on the branches or terminations, 

 and, indeed, the microscopic ganglia, so far as is hitherto 

 known, on the nervi carotid, in the pharyngeal plexus, in the 



