GANGLION CELLS IN THE HEART. 199 



berg 1 (and Ludwig) discovered that, after the administration of nicotine, stimu- 

 lation of the vagus in the frog always produced acceleration, and concluded 

 from their experiments that the vagus of the frog contained accelerator fibres 

 as well as inhibitors. Previously to this, v. Bezold, 2 in 1862 and 1866, had 

 shown, by section of the cord in the upper thoracic region and stimulation of 

 the cervical cord, that accelerating fibres left the spinal cord of mammals to 

 reach the heart at the region of the first thoracic ganglion ; and the brothers 

 Cyon, 3 in 1867, showed that destruction of the ganglion stellatum removed 

 this accelerating effect of stimulation of the cervical cord. Finally, in 1871, 

 Schmiedeberg 4 and Ludwig traced out the course of the accelerator nerves in 

 the dog, and thus completed the proof of Weber's suggestion, that the sym- 

 pathetic nerves to the heart produce the opposite effect to the vagus nerves. 



This paper of Ludwig and Schmiedeberg definitely settled the 

 anatomical course and position of the accelerator nerves in the mammal, 

 and we see that, whereas the inhibitory nerves were first discovered in 

 the vagus of the frog, and then found to exist in the same nerve in the 

 mammal, the accelerator fibres were first discovered in the mammal, and 

 it was supposed for some time that the accelerator fibres in the vagus of 

 the frog belonged to that nerve, and that therefore the cold-blooded 

 differed from the warm-blooded animal in this important respect ; in 

 fact, one finds, even up to the present day, in the literature of the inner- 

 vation of the heart, continued assertions that what is true for the cold- 

 blooded heart is not necessarily true for the warm-blooded, as the 

 differences between them are so great. 



In 1881 5 I read a paper before the International Medical Congress, 

 London, the substance of which was afterwards (1882) published more 

 fully in the Philosophical Transactions of the Royal Society, in which I 

 showed, among other things, that the frog's vagus on stimulation was 

 able to cause not only acceleration, but also very striking augmentation 

 of the force of the contractions both of the auricle and ventricle. 

 Heidenhain, 6 in 1882, described the same thing; and further showed 

 that stimulation of the medulla oblongata, with the cord cut just below 

 it, never produced either acceleration or augmentation, but only pure 

 inhibitory effects. From this he concluded that the accelerator fibres 

 in the vagus did not leave the medulla oblongata in the roots of the 

 vagus nerve, but joined the vagus after its exit from the brain. 



In order to clear up the question of the accelerators in cold-blooded 

 animals, and to determine definitely their course, I determined to in- 

 vestigate them in the higher cold-blooded animals, and for that purpose 

 obtained, through the kindness of Sir Joseph Fayrer and Dr. Kynsey 

 of Colombo, a number of young crocodiles from Ceylon. I was rewarded 

 by finding a very definite accelerator nerve, which arose from the first 

 ganglion below the cervical region and passed directly to the heart. 7 

 Passing to the tortoise, 8 I found that here also accelerator nerves passed 

 from the ganglion belonging to the first nerve posterior to the brachial 



1 Ber. d. Jc. Sachs. Gesellsch. d. Wisscnsch., Leipzig, 1870. 



- " Untersuch. ueber die Innervation des Herzens," 1863; and v. Bezold u. Bever, 

 Untersuch. a. d. physiol. Lab. in Wiirzburg, 1867, Bd. ii. 



3 Arch. f. Anat., Physiol, u. wisscnsch. Med., 1867. 



4 Ber. d. k. Sachs. Gesellsch. d. Wisscnsch., Leipzig, 1870. 



5 Trans. Intcmat. Med. Congress, London, 1881, p. 254. 



6 Arch./, d. yes. Physiol., Bonn, 1882, Bd. xxvii. S. 388. 



7 Joum. Physiol., Cambridge and London, 1884, vol. v. p. 46. 



8 Gaskell and Gadow, ibid., vol. v. p. 362. 



