SECTION OP GLAND ULAR NER VES. \ 519 



plex to allow a definite conclusion to be arrived at. In any adequate discussion 

 of the matter, the facts regarding the production of electric currents in other 

 parts of the body, and especially in the skin and mucous membrane, would 

 have to be taken into account. One or two points only we can mention here. 

 In the skin and mucous membranes of the frog and other animals investigated, 

 there is generally an ingoing electric current, which is increased ,by weak 

 stimulation. Hermann l considers both currents to be due to an " apobiotic " 

 change in the protoplasm. By " apobiotic " is meant any change which 

 diminishes the vital energy of a part of the protoplasm, compared with the 

 rest ; such as is produced by stimulation, the act of dying, the change of proto- 

 plasm to mucin or to keratin, and so forth. Parts undergoing apobiotic 

 change are negative to the rest of the protoplasm. Thus, in a mucous cell, 

 the inner mucous portion of the cell becomes negative to the outer proto- 

 plasmic part, and a current is then set up, which passes in the galvanometer 

 from capsule to hilus, and in the gland from mucous to protoplasmic portion, 

 i.e. there is an ingoing current. As to the outgoing current, Hermann is 

 inclined to consider it as a simple diminution (negative variation) of the 

 normal ingoing or secretory current ; whilst Biedermann advocates the view 

 that the outgoing current is due to anabolic (assimilatory) processes in the 

 gland-cells. 



SECTION OF GLANDULAR NERVES. THE PARALYTIC SECRETION. 



Claude Bernard 2 was the first to make observations upon the effect 

 of section of glandular nerves. He found that section of the chorda 

 tympani in the dog caused the submaxillary gland in two or three days 

 to enter into a state of slow continuous secretion. The slow flow of 

 saliva continued for five to six weeks, and then stopped. During this 

 time the gland itself diminished more and more in size. 



Since the secretion is the result of the section of nerve-fibres, it has 

 been called the " paralytic secretion." Claude Bernard attributed the 

 secretion to the complete removal of nervous impulses. Thus the flow 

 of saliva did not begin for two or three days, because the terminations 

 of the chorda tympani in the gland required two or three days to 

 degenerate completely. It stopped in five to six weeks, because then, 

 he thought, the chorda fibres had regenerated. 



The question was taken up a few years later by Heidenhain. 3 In 

 order to exclude the possibility of the paralytic secretion being caused 

 by irritation of the duct or gland, he cut the chorda tympani in the 

 tympanic cavity. The secretion occurred in the same way as when the 

 nerve was cut peripherally of the ganglion, then called the submaxillary 

 ganglion (cf. above, p. 481). It began in twenty-four hours at least, 

 i.e. considerably earlier than the time given by Bernard. It was watery, 

 and contained very little mucin ; it contained many leucocytes (amoe- 

 boide Korperchen), and was in consequence somewhat cloudy. The 

 secretion was at first very slow, but gradually increased in rapidity, so 

 that in about a week a large drop might be secreted every twenty 

 minutes. After three weeks it diminished markedly. The gland itself, 

 as its size diminished, became of a yellowish tint, and waxy appearance. 



The time taken by the peripheral ends of the cut chorda tympani 



1 Arch. f. d. ges. PhysioL, Bonn, 1894, Bd. Iviii. S. 246. References to much of the 

 earlier work will be found in this paper. 



2 Journ. de I'anat. etphysiol., etc., Paris, 1864, tome i. p. 507. 



:! Stud. d. physiol. Inst. zu Breslau, Leipzig, 1868, Heft 4, p. 73. 



