6x8 SYMPATHETIC AND OTHER SYSTEMS OF NERVES. 



animals in the skin and adjoining mucous membrane of the nose and lips, 

 and in the mucous membrane of the hard palate ; it is less marked in the 

 gums and mucous membrane of the cheeks, and slight only in the tongue. 



4. Dilatation of vessels in the 'bucco-facial region of the dog. This was 

 first shown by Dastre and Morat. 1 They found that strong and moder- 

 ately strong stimulation of the cervical sympathetic produced intense 

 flushing in the mucous membrane of the lips, gums, cheeks, hard palate, 

 nose, and in the neighbouring parts of the skin. With weak currents 

 the first effect produced is contraction of the blood vessels. In other 

 animals, primary contraction appears always to be produced, whatever 

 the strength of the current. Thus the occurrence of vaso-dilator fibres 

 at any rate in sufficient number to overcome the vaso-constrictor 

 fibres is, so far as we know, peculiar to the dog. In this animal they 

 are probably of use in regulating the temperature of the body. 



5. Secretion* from the salivary glands, the lachrymal glands, the 

 glands of the mucous membrane of the mouth, nose, and pharynx, and 

 from the sweat glands of the skin where these occur. 



6. Erection of hairs 3 in animals which have erectile hairs. In the 

 cat, erection of hairs is obtained in a triangular area between the eye 

 and ear, the base of the triangle lying in front of the ear; in the 

 occipital region, and occasionally in the whole dorsal region of the 

 head ; and in the skin of the back of the neck supplied by the third 

 cervical nerve. In the ape it is obtained on the forehead, on the 

 anterior half or more of the scalp, on the temple and cheek. 



In the hedgehog the cervical sympathetic causes erection of quills 

 in the head and upper part of the neck. 4 The cervical sympathetic 

 causes in the dog slight contraction of the angle of the nostril, and in 

 the ape slight retraction of the pinna of the ear. 



All of the above actions are well established. Others have been 

 described, about which opinion is conflicting, and the evidence is not 

 satisfactory. Such 5 are contraction and dilatation of the vessels of the 

 retina, inhibition of the ciliary muscle and the sphincter pupillse, and, 

 notably, .contraction and dilatation of the arteries of the brain. 



Some early observations on the cervical sympathetic. Petit, 6 in 

 1727, described in the dog certain effects of section of the vagus in the neck, and 



1 Dastre and Morat, Compt. rend. Acad. d. sc., Paris, 1880, tome xci. pp. 393, 441 ; cf. 

 also Bochefontaine and Vulpian, Compt. rend. Soc. de bioL, Paris, 1880, p. 319 ; Dastre and 

 Morat, "Systeme nerveux vaso-moteur," Paris, 1884, p. 102; Morat, Arch, de physioL 

 norm, etpath., Paris, 1898, p. 204 ; Langley and Dickinson, Proc. Roy. Soc. London, 1890, 

 vol. xlvii. p. 380. 



2 See articles on "Salivary Glands and on Secretion by the Skin," Vol. I. p. 475. 



3 Langley and Sherrington, Journ. PhysioL, Cambridge and London, 1891, vol. xii. p. 

 278 ; Langley, ibid., 1893, vol. xv. p. 176. Cf. also H. Mliller, Wiirzb. naturw. Ztschr., 

 1861, Bd. ii. S. 54 ; Schiff, Imparziale, Firenze, Anno x. 



4 Langley, " Proc. Physiol. Soc.," 1893, vol. i. ; Journ. PhysioL, Cambridge and London, 

 vol. xiv. For the effect of the cervical sympathetic on the wattles, the feathers, and the 

 eye in the fowl and turkey, cf. Schiff (1862 and 1867), Oesam. Beitr., Lausanne, 1894, Bd. 

 i. S. 183 ; Jegorow, Arch. f. d. ges. Physiol., Bonn, 1887, Bd. xli. S. 326 ; Arch. f. PhysioL, 

 Leipzig, 1890, Suppl., S. 33. 



5 Cf. Jegorow, Arch. f. PhysioL, Leipzig, 1886, S. 174 ; Morat and Doyon, Arch, de 

 physioL norm, et path., Paris, 1892, p. 60 ; ibid., 1891, p. 507 ; Jessop, Proc. Roy. Soc. 

 London, 1886, vol. xl. p. 478; Langley and Anderson, Journ. PhysioL, Cambridge and 

 London, 1892, vol. xiii. p. 583. For innervation of the vessels of the brain, cf. this 

 Text-Book, article on "Circulation." 



6 Hist, de VAcad. Roy. des Sc., 1727. Cf. also Dupuy, Joum. de med., chlr. etpharmacoL, 

 Bruxelles, 1816, tome xxxvii. ; Reid, "Physiological, Anatomical, and Pathological Re- 

 searches," 1848. 



