366 THE SOLIDS. 



and ramify amongst the ganglion globules in a waved and 

 serpentine manner. 



The arrangement of the ganglion globules and nerve 

 tubules just indicated, tends to show that these are really 

 the only essential elements of a ganglion. 



The ganglia are supplied with blood-vessels. 



It will be apparent from the above description that the 

 ganglia have all the structural characteristics of glands, and 

 therefore there can be little question but that they are really 

 glandular organs, and that the tubular fibres which pass 

 through them carry away the fluid, which is destined to 

 exercise its influence on the parts and organs to which the 

 nerves are themselves distributed. 



The question as to the origin of either the tubular fibre or 

 the gelatinous filament from the ganglionary corpuscles, 

 is still an undecided one, the weight of evidence being op- 

 posed to the idea, that either order of fibres has any origin 

 from these corpuscles. 



ORIGIN AND TERMINATION OF NERVES. 



Origin. But little that is certain is known respecting the 

 exact mode of origin of the numerous tubules composing the 

 nerves, and of the precise relation of these with the cellular 

 or secreting element of the ganglionic centres. The obser- 

 vations of Dr. Lonsdale *, however, render it highly probable 

 that the greater portion at least of the nerve tubes have a 

 looped origin in the brain and spinal cord : that gentleman 

 having made out the interesting fact, that in two foetuses, in 

 the one of which both the brain and spinal cord were deficient, 

 and in the other the brain only, the extremities of the nerves, 

 which extended into the cavities of the spinal column and 

 cranium were made up of looped nerve tubes imbedded in an 

 imperfectly developed granular and cellular matter, apparently 

 of a ganglionic character. Now, from what is known re- 



* Edinburgh Medical and Surgical Journal, No. cxvii. 



