132 PRACTICAL HISTOLOGY. 



get their continuation to the nerve fibres, these being 

 left behind for the most part. The mode of perma- 

 nently preserving the specimen is like that employed 

 in the preceding preparation, except that the cells 

 may with advantage be colored by logwood instead 

 of osrnic acid. 



Terminations of the nerves. The description 

 of the mode of preparing and demonstrating the 

 terminations of nerve fibres in various special parts 

 of the body will be deferred until those parts and 

 organs are severally treated of, but the Pacinian 

 bodies, in which many of the sensory fibres end, and 

 the end-plates in which the nerves supplying the 

 voluntary muscles terminate, may be now prepared. 



Preparation 7. The Pacinian bodies are very 

 readily found in the cat's mesentery. Here they are 

 at once seen when the abdomen is opened and the 

 membrane is held up against the light, as clear, oval 

 specks, either dotted singly here and there, or form- 

 ing groups of two, three, or more. There is generally 

 a considerable group in the meso-rectum, and more- 

 over they are here usually not so much obscured by 

 the adipose tissue as in the mesentery proper. By 

 far the best general idea of their structure and the 

 relation they have to the nerve fibre entering them 

 is obtained from their study in the fresh condition, 

 without the addition of reagents. But it is well to 

 separate them from the surrounding tissue of the 

 mesentery, for this is often loaded with fat, and, 

 when not, the fibrous tissue of the membrane tends 

 to obscure the structure of the little bodies. 



In order to isolate one of them, cut out the piece 

 of the mesentery containing it, carrying one of the 

 cuts close along the edge of the corpuscle. Then 

 place the excised piece upon a slide in a drop of 

 serum, and without actually transfixing the Pacinian 

 itself, tear away the investing mesenteric tissue bit 

 by bit under the dissecting microscope. It will be 

 found that with a little manipulation the corpuscle 

 shells out as a lemon-shaped body, with a twisted 



