THE SALIVARY GLANDS. 677 



their secretions belongs properly to pharmacology, but the effects 

 of the three drugs mentioned are so decided that they have a 

 peculiar physiological interest. Atropin in small doses injected 

 either into the blood or into the gland duct prevents the action of 

 the cerebral autonomic fibers (tympanic nerve or chorda tympani) 

 upon the glands. This effect may be explained by assuming that 

 the atropin paralyzes the endings of the cerebral fibers in the glands. 

 That it does not act directly upon the gland cells themselves seems 

 to be assured by the interesting fact that, with doses sufficient to 

 throw out entirely the secreting action of the cerebral fibers, the 

 sympathetic fibers are still' effective when stimulated. Pilocarpin 

 has directly the opposite effect to atropin. In minimal doses it 

 sets up a continuous secretion of saliva, which may be explained upon 

 the supposition that it stimulates the endings of the secretory fibers 

 in the gland. Within certain limits these drugs antagonize each 

 other, that is, the effect of pilocarpin may be removed by the sub- 

 sequent application of atropin, and vice versa. Nicotin, according 

 to the experiments of Langley,* prevents the action of the secretory 

 nerves, not by affecting the gland cells or the endings of the nerve 

 fibers around them, but by paralyzing the connections between the 

 nerve fibers and the gang lion cells through which the fibers pass on 

 their way to the gland, that is, the connection between the pre- 

 ganglionic and postganglionic fibers. If, for example, the superior 

 cervical ganglion is painted with a solution of nicotin, stimulation 

 of the cervical sympathetic below the gland gives no secretion; stim- 

 ulation, however, of the fibers in the ganglion or between the ganglion 

 and gland gives the usual effect. By the use of this drug Langley is 

 led to believe that the cells of the so-called submaxillary ganglion 

 are really intercalated in the course of the fibers to the sublingual 

 gland, while the nerve cells with which the submaxillary fibers make 

 connection are found chiefly in the hilus of the gland itself. 



Paralytic Secretion. A remarkable phenomenon in connection 

 with the salivary glands is the so-called paralytic secretion. It has 

 been known for a long time that if the chorda tympani is cut the 

 submaxillary gland after a certain time, one to three days, begins to 

 secrete slowly, and the secretion continues uninterruptedly for a long 

 period as long, perhaps, as several weeks and eventually the gland 

 itself undergoes atrophy. Langley states that section of the chorda 

 on one side is followed by a continuous secretion from the glands 

 on both sides; the secretion from the gland of the opposite side he 

 designates as the antiparalytic or antilytic secretion. After section 

 of the chorda the nerve fibers peripheral to the section degenerate, 

 the process being completed within a few days. These fibers, how- 

 ever, do not run directly to the gland cell; they terminate in end 

 * "Proceedings of the Royal Society," London, 46, 423, 1889. 



