676 SECRETION AND ABSORPTION BY THE SKIN. 



hen. It contains fat, a proteid clotting with rennet, globulin, salts, and water, 

 but is free from sugar. 1 



The secretion of the leg glands of lizards is probably of sebaceous nature. 2 

 In certain fish, in addition to the secretion of slime by the goblet cells of 

 the epidermis, a formation of fibrils takes place from specialised cells, termed 

 " club cells," which may be distributed in the general epidermis or located in 

 special glandular involutions, as in the Myxinoid fishes. This secretion reaches 

 its highest development in the Myxinoids, and accounts for the extraordinarily 

 tenacious slime of this class. The process has, however, also been observed in 

 the case of the eel and lamprey. 3 



MECHANISM OF THE SECRETION OF SWEAT. 



- 



Goltz 4 in 1875 discovered the fundamental fact that excitation of 

 the peripheral end of the divided sciatic causes the appearance of beads 

 of sweat on the hairless pads of the hind-foot of the cat. He also saw 

 the same effect in a dog. In the next year, Ostroumow, 5 and Kendall 

 and Luchsinger 6 confirmed the result, and extended the details of the 

 experiment. 



Ostroumow showed that excitation of the abdominal sympathetic 

 cord produced the same effect ; that even after ligature of the aorta, sweat 

 was still secreted upon excitation of the appropriate nerves ; and, finally, 

 that injection of atropine completely annulled the effect of such excita- 

 tion. 



Kendall and Luchsinger obtained the effect upon the fore-leg of the 

 cat and dog, by exciting the nerves of the brachial plexus, confirmed 

 the fact of the persistence of secretion after occlusion of the aorta, or 

 crural artery in the case of the hind-limb, and further showed that, even 

 after amputation of the leg, sweat could be produced on the pads of the 

 foot for some fifteen to twenty minutes, by stimulation of the sciatic. 



The fact that the production of sweat is an act of true secretion, 

 and the existence of sudorific fibres having been demonstrated, the 

 course of the fibres from the spinal cord next engaged attention. 



The existence of sweat-fibres for the lower limb in the abdominal 

 sympathetic cord, demonstrated by Ostroumow, was confirmed by 

 Luchsinger 7 and Nawrocki, 8 and extended by both the latter observers 9 

 to the thoracic sympathetic cord, for the fore-limb. Later, sudorific 

 fibres for the face, running in the cervical sympathetic, were demon- 



1 John Hunter, " Observations on Certain Parts of the Animal OZconomy," London, 1786, 

 p. 191 ; Hasse, Ztschr. f. rat. Med., 1865, Reihe 3, Bd. xxiii.; Claude Bernard, "Les 

 liquides de 1'organisme," Paris, 1859, tome ii. p. 232; Teichmann, Arch. f. mikr. Anat., 

 Bonn, 1889, Bd. xxxiv. S. 225 ; Charbonnel-Salle et Phisalix, Compt. rend. Acad. d. sc., 

 Paris, 1886, tome eiii. p. 286 ; Phisalix, Compt. rend. Soc. de biol., Paris, 1890, Ser. 9, tome 

 ii. p. 368 ; Reid, Hep. Brit. Ass. Adv. Sc., London, 1894, p. 812. 



2 Leydig, "Die in Deutschland lebenden Arten der Saurier," 1872; Batelli, Arch. f. 

 mikr. Anat., Bonn, 1879, Bd. xvii. S. 346. 



3 J. Miiller, "Untersuch. ii. die Eingeweide der Fische," Berlin, 1845, S. 11 ; Eolliker, 

 Wurzb. med. Ztschr., 1860, Bd. i. S. 1 ; F. E. Schulze, Arch. f. mikr. Anat., Bonn, 1867, 

 Bd. iii. S. 137 ; Fcettinger, Bull. Acad. roy. d. sc. de Belg., Bruxelles, 1876, Ser. 2, tome 

 xli. p. 599 ; Blomfield, Quart. Journ. Micr. Sc., London, 1882, vol. xxii. p. 355 ; Reid, 

 Phil. Trans., London, 1894, vol. clxxxv. p. 319. 



4 Arch. f. d. ges. Physiol., Bonn, 1875, Bd. xi. S. 71. 



5 Ref. in Jahresb. ii. d. Fortschr. d. Anat. u. Physiol., Leipzig, 1877, Bd. v. 



6 Arch.f. d. ges. Physiol., Bonn, 1876, Bd. xiii. S. 212. 



7 Ibid., Bonn, 1877, Bd. xiv. S. 369. 



8 CentralU. f. d. med. Wissensch., Wien, 1878, S. 2. 



9 Nawrocki, Centralbl. f. d. med. Wissensch., Berlin, 1878, S. 17 ; Luchsinger, ibid., 

 1878, S. 36. 



