26 



NERVOUS SYSTEM. 



FIG. 2. 



granulations, and a number of oval, longitudinal nuclei, a 

 characteristic which has given them the name of nucleated 

 nerve-fibres. The diameter of the fibres is about -g^or f 

 an inch. The nuclei have nearly the same diameter as the 

 fibres, and are about y^Vtr of an inch in length ; l they are 

 finely granular, and present no nucleoli. The fibres are 

 rendered pale by the action of acetic acid, but they are 

 slightly swollen only, and present, in this 

 regard, a marked contrast with the ele- 

 ments of a connective tissue. The micro- 

 scopical appearances of these fibres, which 

 are strongly characteristic, are represented 

 in Fig. 2. 



Accessory Anatomical Elements of the 

 Nerves. The nerves present, in addition 

 to the different varieties of true nerve- 

 fibres just described, certain accessory ana- 

 tomical elements common to nearly all of 

 the tissues of the organism, such as con- 

 nective tissue, blood-vessels, and perhaps 

 lymphatics, though these have never been 

 demonstrated, except in the nerve-centres. 



Like the muscular tissue, the nerves are 

 made up of their true anatomical elements, 

 the nerve-fibres, held together into primi- 

 tive, secondary, and tertiary bundles, and 



nified 800 diameters. . . . . . r . .^ 



with the gelatinous so on, in proportion to the size ot the nerve. 

 of S ordinarydari^ The primitive fasciculi are surrounded by 



bordered nerve-fibres. IT i i ' i -i T> i 



(LITTRE ET KQBIN, a delicate membrane, described by Hob in 



l)ictionnaire de me- -, .-, /,/.* 01^ -i i 



1865, p. under the name ot pertnevre, but which 

 had been already noted by other anato- 

 mists under different names. 3 This membrane is homoe- 



mag- 





1 LITTRE ET ROBIN, loc. tit. 



2 LITTRE ET ROBIN, Dictionnaire de mededne, Paris, 1865, Article, Fcrinevre. 

 8 KOLLIKER, Elements (Thistelcgie humainc, Paris, 18G8, p. 317. 



