REFLEX ACTION OF PERIPHERAL GANGLIA. 523 



irritability ; in the cat, according to Bradford, it gives no secretion three 

 days after section. 



Stimulation of the ganglion will still cause secretion and pallor of 

 the gland for several weeks after section of the nerve, and possibly 

 indefinitely. 



Excision of the superior cervical ganglion has also no certain effect 

 upon the salivary glands, and does not give rise to a secretion. In the 

 rabbit I could see no decrease in the size of the submaxillary glands, 

 or alteration in their histological appearance, nine, sixteen, and twenty- 

 three days respectively after removal of the ganglion, nor in a case in 

 which the ganglion had been removed five years previously by Dr. Pye- 

 Smith. The chorda tympani still causes secretion and flushing of the 

 gland, though the flushing is apparently less than normal. Bradford 

 removed the superior cervical ganglion in the cat. He found no atrophy 

 of the gland up to seven weeks after the operation ; indeed, in his cases 

 both the submaxillary and the parotid glands were somewhat heavier 

 on the operated than on the sound side. Eemoval of the ganglion 

 causes the sympathetic filaments on the gland artery to degenerate, the 

 loss of irritability being fairly rapid ; thus, three days after the operation, 

 Bradford obtained no secretion on stimulating these nerve-filaments. 



SECRETION DUE TO A REFLEX ACTION OF PERIPHERAL GANGLIA. 



We may reject the view of Bernard, 1 that a secretion can be 

 obtained from the submaxillary gland of the dog, by means of nervous 

 impulses passing from the mucous membrane of the tongue by the 

 lingual nerve to the " submaxillary " ganglion, and thence to the gland. 

 The direct proof alleged in favour of this view was that occasionally, 

 after section of the chordo-lingual, direct stimulation of the tongue, or 

 the application of ether, caused a slight secretion. As no anaesthetics 

 were given, it is quite possible that a slight flow from the duct might be 

 caused by reflex movements. The result was not obtained by Eckhard, 

 Bidder, and others ; and until it can be obtained with some constancy, 

 and after administering at any rate a moderate amount of anaesthetics, it 

 may properly be disregarded. 



The indirect proof alleged is that after section of the chordo-lingual, 

 stimulation of the lingual on its course to the tongue (the nerve being 

 cut and the central end stimulated) causes a secretion from the sub- 

 maxillary gland. This, in fact, is commonly the case. The amount of 

 the secretion, broadly speaking, increases the nearer the electrodes are to 

 the chorda tympani. It is often barely more than perceptible. The 

 fact observed by Bernard, that three to five days after section of the 

 chordo-lingual, a secretion could no longer be obtained, seems sufficient, 

 with our present knowledge of the central nervous system, to show that 

 the lingual secretion cannot be reflex in the ordinary sense. 



There can be little doubt that Schiff 's 2 explanation is in the main 

 correct, namely, that some secretory fibres for the submaxillary gland, 

 instead of running to it direct by the chorda tympani, accompany the 

 lingual for a short distance and then run back to the gland. Schiff 



1 Journ. de I'anat. et physiol., etc., Paris, 1864, tome i. p. 507. For some further 

 account of the earlier papers, see Foster's "Text-book of Physiology," 1879, 3rd edition, p. 



2 "Lesons sur la physiol. de la digestion," 1867, tome i. p. 284. 



