504 GENERAL ANATOMY. 



series: he ranges in the first the rachidian or spinal; in the 

 second those which are found in the course of the trisplanch- 

 nic; and all that are situated more internally in the third. 

 Wutzer divides them into ganglions of the cerebral system, of 

 the spinal system, and of the vegetative or sympathetic sys- 

 tem. I divide them into two kinds: list, the ganglions of the 

 encephalo-spinal nerves, some, the most numerous and the 

 most regular, belonging to the nerves with double roots, 

 others placed in the course of the nerves with a single root; 

 2d, the ganglions of the two sympathetic nerves, some form- 

 ing a double longitudinal series, and others near the median 

 line. 



796. The number of ganglions is very great, as will be 

 seen. They are all situated in the trunk; Lancisi was wrong 

 in stating that they existed in the members. Their size varies 

 from that of an olive to that of a grain of millet; their form 

 is round, ova! 5 lenticular, &c. 



797. The ganglions are composed of two internal sub- 

 stances: the first medullary and white; the second pulpy and 

 of a reddish gray. The medullary substance is collected into 

 cords and filaments, like the sensorial and motory nerves. 

 These interior medullary filaments are visibly the continua- 

 tion of the nerves, connected with the ganglions. The coeli- 

 ac ganglion is the only one where this continuation is not 

 clearly manifest. These filaments are recognized by their co- 

 lour and form. The action of alkalies and acids, upon them, 

 renders them manifest, even in the midst of the ganglions, as 

 nervous medullary filaments. 



These filaments, on penetrating the ganglions, become de- 

 prived of their neurilema, which unites intimately with the 

 exterior membrane of the ganglion. These filaments have 

 their surface less exactly defined than in the nerves; their sur- 

 face appears more loose, as if blended or intimately united 

 with the adjacent substance. These medullary filaments have 

 otherwise considerable tenacity. 



79S. The second substance of the ganglions establishes 

 not only the difference between the nerves and ganglions, but 

 between the ganglions and the plexuses. This substance has 



