208 % SPECIAL HISTOLOGY. 



wall of the cavity besides the panniculus also presented a corium with 

 papillae, and an epidermis like the external integument. 



Method of Investigation. To examine the position of the sudoriparous 

 glands and their excretory ducts, fine sections of fresh or slightly-dried 

 skin of the palm or sole should be prepared, and made transparent by 

 acetic acid or caustic soda. Gurlt used for this purpose skin hardened 

 and rendered transparent in a solution of carbonate of potassa (liquor 

 kali carbonici). Giraldes macerates the skin for twenty-four hours in 

 dilute nitric acid (1 part acid, 2 parts water), and for twenty-four hours 

 in water, a process which, according to Krause, is very useful, as the 

 glands become yellow, and are readily distinguished. In macerated 

 pieces of the skin, the cellular lining of the sweat-ducts may be drawn 

 out of the corium, in the form of long tubes, with the epidermis ; in 

 delicate parts of the skin I have, not unfrequently, succeeded in doing 

 this after treatment with concentrated acetic acid. The investigation 

 of the glandular coils themselves is very easy in the axillary glands ; in 

 the others the skin must be prepared from within, and the glands sought 

 for partly upon the inner surface of the cuts, partly in its meshes, a 

 method which readily succeeds, with a little attention, particularly in 

 the hand, foot, and nipple. The large glands of the ball of the foot of 

 the Dog, described by Gurlt, are particularly well-fitted for demonstra- 

 tion, and still more those of the prepuce and of the integuments of the 

 udder of the Horse, which lie quite loose in the subcutaneous tissue. If 

 it be desired to count the glands, their apertures may be sought for, or 

 a piece of skin of determinate size may be treated according to Giraldes' 

 method, and examined portion by portion (Krause). For the study of 

 the development of the glands, sections of the fresh and dried skin of 

 the heel and palm of embryos, may be made with the double knife or 

 razor. In embryos preserved in spirit, if the sections be fine, the glands 

 may also be very well seen, especially in the first moments of the action 

 of caustic soda. 



Literature. Breschet et Roussel de Vauzeme, "Recherches ana- 

 tomiques et physiologiques sur les appareils tegumentaires des animaux," 

 in the " Annales des Sciences Nat.," 1834, pp. 167 and 321 (discovery 

 of the sudoriparous glands) ; Gurlt, " Vergleichende Untersuchungen 

 iiber die Haut des Menschen und der Haussaugethiere, besonders in 

 Bezug auf die Absonderungsorgarie des Hauttalges und des Schweisses," 

 in Muller's " Archiv," 1835, p. 399 (first good figures of the glands 

 themselves). [Robin, " Note sur une espece particuliere des glandes de la 

 peau de 1'homme," in the "Annales des Sciences Nat.," 1845; Homer, 

 " On the Odoriferous Glands of the Negro," in American Journal of 

 Med. Sciences, 1846.] Besides these, compare especially the general 

 works of Todd and Bowman, Henle, Valentin, Hassall, and myself; the 

 above-cited treatises of Krause, myself, Simon, Von Biirensprung, and 

 Wilson ; further the figures of Berres, tab. XXIV. ; R. Wagner, "Icon. 



