742 



THE NERVOUS SYSTEM IN GENERAL. 



nerves of organic life, possess a greater quantity of slender tubes than the others. 

 These tubes are commonly designated as the organic nerve-fibres. They also 

 contain fibres of Remak. 



In the spinal (janglia, the cells are joined, to the nerve-tubes. It has been 



Fig 41.;. 



Fig. 413. 



MICROSCOPIC GANGLION FROM HEART 

 or FROG. 



BIPOLAR GANGLIONIC CELLS AND NERVE- 

 FIBRES, FROM GANGLION OF FIFTH PAIR 

 IN LAMPREY. 



shown, by dissection and microscopical observation, that the corpuscles com- 

 posing the ganglia or expansions at the origin of the nerves, are all attached to 

 the superior fibres. The other tubes have none. 



In the cerebrospinal axis, the two substances are equally associated, and 



Fi2. 414. 



Fig. 415. 



STELLATE NERVE-CELL, FROM THE NUCLEUS 

 CERVICIS CORNU (POSTERIOR VESICULAR 

 column) OF A FCETUS OF SIX MONTHS, 

 MAGNIFIED 420 DIAMETERS. 



8TRUCTUBB OF GANGLIONIC NERVE-CELL. 



A, According tn Beale ; B, according to Arnoldo 

 a, Straight fibre; 6, double spiral fibre; c, 

 capsule of connective tissue. 



connected with each other by a prolongation (or single pole) which is inflected 

 in such a manner as to resemble a T or Y (cells with T-shaped fibres), but in a 

 variable manner, according to the region. In the spinal cord and its prolonga- 

 tions into the encephalon, the grey substance occupies the interior : while it is 

 spread over the exterior of the encephalic lobes, and envelops the white substance. 



I 



