BY DR. KLEIN. 95 



terminate close to the epithelium in a dense network of pale 

 fibres, extending equally on both sides of the tail so as to form 

 a continuous sub-epithelial layer. As no nerve fibres can be 

 traced beyond this network, we are entitled to conclude that 

 the nerves terminate in it. 



Nerves of the Mucous and Serous Membranes. 

 Thin strips of fresh mucous membrane are cut from the vagina 

 or mouth of the dog or rabbit, and are placed for from forty- 

 five to sixty minutes in half per cent, solution of chloride of 

 gold, and are then, after having been washed with distilled 

 water, transferred to a solution of tartaric acid, hardened in 

 alcohol, and employed for the preparation of sections in the 

 manner already explained. The nervous trunks which are 

 distributed to the mucous membrane consist mostly of medul- 

 lated fibres, and give off branches which, resolve themselves 

 into a network of fine non-medullated fibres, lying immedi- 

 ately beneath the epithelium, and the films of this network are 

 beset with nuclei, which are either far apart, as in the vaginal 

 mucous membrane of the dog, and in the oral and vaginal 

 mucous membrane of the rabbit, or more frequent, as in the 

 mouth of the dog. From this network, filaments having vari- 

 cosities of various sizes, find their way into the epithelium, 

 and give off branches to the different layers of epithelium 

 which combine into a network, some of which appear to end 

 in a knob-like swelling. In the middle layers they are in com- 

 munication with branched nerve-cells: there is no evidence 

 of any connection between them and the branched cells of the 

 mucosa. 



Nerves of the Septum Cisternse and of the Mesen- 

 tery of the Frog or Newt. It is comparatively difficult 

 to demonstrate non-medullated nerves in these parts by means 

 of the ordinary method of staining with gold. It can be 

 done in the following way successfully : The fresh membrane 

 is placed for from forty-five to sixty minutes in solution of 

 gold ; thereupon it is exposed to the light for several days in 

 distinctly acid water. As soon as the preparation has ac- 

 quired a markedly reddish or grayish-violet tint, it is pencilled 

 on both sides so as to remove the endothelium, and placed for 

 ten minutes in diluted, distinctly alkaline solution of carmine. 

 It is then washed in acidulated water and covered in glycerin. 

 From the winding nervous trunks which accompany the larger 

 vessels of the mesentery, numerous small twigs branch off' in 

 great numbers, consisting of very numerous non-medullated 

 fibres, which combine to form a network. Although these 

 fibrils are much more numerous than has been hitherto sup- 

 posed, they never terminate by a free end, but always take 

 part in the formation of a network. (The numerous non-medul- 



