GENERAL HISTOLOGY^ OF THE NERVOUS SYSTEM. 119 



the most rapid and successful methods is by the use of hsema- 

 toxylin. The pneumogastric nerve of a cat is removed and 

 immediately placed in the hsematoxylin solution ; then, after 

 thorough staining, which may only take a few minutes, in 

 dilute acetic acid (^ per cent.), and finally mounted in gly- 

 cerine. In this way the nuclei will be stained a beautiful pur- 

 ple, while the fibres will be unaffected. The number of nuclei 

 and absence of medulla will serve to distinguish the fibres of 

 Eemak from the medullated. It is difficult by any method of 

 preparation to see that there are any precise limits to the lon- 

 gitudinal lines in the fibres, i.e., that the striation is due to 

 little, short, narrow rods, lying side by side (Ranvier). The 

 nitrate of silver demonstrates no transverse markings and no 

 constrictions or crosses. There is but little likelihood in these 

 specimens to mistake the fibres for connective- tissue bundles. 

 In the first place, the nuclei, and what cell-bodies happen to 

 be about them, of the one, are small, flattened, ovoid bodies 

 occurring at pretty regular intervals, while the connective-tis- 

 sue corpuscles are usually larger, longer, and, though they 

 may appear oat- shaped, when the side is turned to the observer, 

 are broad plates with irregular edges when seen flatwise. In 

 the second place, the fibres run their course in long, narrow 

 bundles, as no connective tissue does. 



Ganglionio bodies. Of these there are three kinds : 1. 

 Those that are connected with the spinal and some cerebral 

 nerves. 2. Those found in the gray substance of the brain and 

 spinal cord. 3. Those in the ganglia of the sympathetic sys- 

 tem. These bodies are of such large size that they may often 

 be seen with the naked eye. In the human species they are 

 usually in close connection with the origin of the nerves, though 

 they also may be interspersed at points through the course of 

 the fibres or may be present near their points of distribution 

 (ganglia of AuerbacTi). Their immediate connection with the 

 nerve-fibre is made in the following ways : 1. A large process, 

 which does not at first appear to branch, passes off, and is 

 continuous with the axis- cylinder. 2. Fine branches are given 

 off from one or more corpuscles, and, uniting, contrive to form 

 a nerve-fibre (either a fibre of Eemak or a myelinic fibre). 3. 

 These branches after combination may pass through a gangli- 

 onic corpuscle, which then is called bipolar (Gerlach, Wal- 

 deyer). In the sympathetic system we have the unbranched 



