X.] STRUCTURE OF NERVOUS TISSUES. 113 



E. Sympathetic Ganglia. 



Place a sympathetic ganglion e.g. the superior 

 cervical sympathetic ganglion of a rabbit in 

 1 p.c. osmic acid for a day. Wash it with water 

 and leave it in water for some hours. Transfer to 

 50 p.c. spirit for an hour, then to strongspirit for 

 a week. Cut longitudinal sections and observe 



a. The large number of nerve-cells of various 

 sizes. 



b. The small number of meduUated nerves com- 

 pared with the spinal ganglion (D § 2 a). 



c. The small size of nearly all the medullated 

 nerves (cp. D % 2d), when these are in 

 bundles they are usually at the periphery 

 of the ganglion. 



d. The bundles of non-meduUated nerve-fibres 

 at the ends of the ganglion; the distinctness 

 with which these are seen will of course vary 

 in diflferent sections. 



Dissection of Sympathetic Ganglia in the Frog. Lay 

 open the abdomen of a recently killed frog, pick iip 

 the intestine and cut through, the mesentery just 

 above the kidneys; pulling up one kidney, cut 

 through the peritoneum along its edge, and turn 

 over the kidney to the opposite side of the body. 

 Gently stretch the spinal nerves away from the 

 spinal column, a row of small nerve fibres will be 

 seen running transversely from the spinal nerves 

 (one from each nerve) to the chain of pigmented, 

 semi-transparent sympathetic ganglia which will be 

 seen lying over the spinal column. 

 L. 8 



