5 2 2 THE SALIVAR Y GLANDS. 



stimulating the postganglionic chorda fibres, and by injecting pilo- 

 carpine, was distinctly viscid, and more viscid than normal. The alveoli 

 mentioned by Heidenhain were, I am inclined to think, the demilunes 

 which a decrease in the size of the mucous cells inevitably brings into 

 prominence, notwithstanding an actual decrease in the size of the 

 individual demilune cells. 



Stimulation of the cervical sympathetic, during the progress of the 

 paralytic secretion, has practically its normal action both in the dog and 

 the cat. In the dog, it gives, when- stimulated after a sufficient interval 

 of rest, a brief quick now of watery saliva, corresponding with the 

 augmented secretion, and after this a slow slight secretion even thicker 

 than usual. If the stimulus be prolonged, there is a long pause in the 

 paralytic secretion, due partly to anaemia of the gland, and partly to the 

 resistance offered to the now by the thick saliva in the lumina and 

 ducts. In the cat, the sympathetic produces secretion in the usual way 

 and of the usual kind ; and unless the stimulation be too prolonged, the 

 paralytic secretion slowly creeps on in the intervals between the several 

 stimulations. 



Heidenhain noticed in the dog that section of the chorda tympani on 

 one side caused a slight continuous secretion from the submaxillary 

 gland of the opposite side. The occurrence of such a secretion I con- 

 firmed in the cat. It is convenient to have a name for this secretion, 

 and I have called it the antiparalytic, or, more briefly, the antilytic 

 secretion. In my experiments the antilytic secretion was stopped by 

 apncea and by excess of chloroform. Dyspnoea caused a secretion 

 apparently greater than normal, though less than on the paralytic side. 

 No certain antilytic secretion was observed either thirteen or forty-two 

 days after section of the chorda. In its early stage, three days after 

 section of the opposite chorda, it was diminished by cutting the chorda 

 of the same side, and abolished by cutting the sympathetic also. So far, 

 then, as regards the cat, there is some ground for thinking that the anti- 

 lytic secretion is transitory and due to impulses set up in the central 

 nervous system. 



Section of the chorda tympani probably leads to slow changes in the nerve- 

 cells of the secretory centre which are connected with the chorda fibres ; 

 these changes might make the central nerve-cells more irritable, so that they 

 passed into a condition of continuous slight activity, thus producing the anti- 

 lytic secretion. Or the antilytic secretion might, as suggested by Bradford, be 

 simply a reflex from the tissues injured during the section of the chorda. 



According to Heidenhain, the antilytic secretion in the dog continues after 

 section of both chorda tympani and sympathetic nerves. As it is difficult to 

 see why the local mechanism should be so easily thrown out of gear, it is best 

 to wait for further observations on the matter. 



Little is known as to the time taken for the chorda tympani fibres to 

 regenerate. In a puppy, I obtained, three months after section of the chorda 

 tympani, a secretion much as usual, on stimulating either the nerve which had 

 been cut or the chordo-lingual, so that presumably regeneration is fairly com- 

 plete in three months. 



Section of the cervical sympathetic x has no observable permanent effect 

 upon the gland, and it causes no paralytic secretion. The blood vessels 

 for a time dilate, but this soon passes off. The nerve soon loses its 



1 Cf. Langley, op. cit,., and Bradford, op. cit. 



