SECT. 76, 77.] MUSCULAR SYSTEM. I4I 



in diameter, with saccular dilatations of o'o4'" to o'n'" in diameter, which 

 were often arranged in groups behind each other, and wholly filled with se- 

 baceous matter. Occasionally a small hair lay in such a duct, so that the 

 latter appeared at the same time as a hair-follicle. 



In investigating the sebaceous (/lands, they may be dissected either from 

 within and separated with their hair-follicles from the skin, or perpendicular 

 sections of the skin may be made, which, however, should not be too fine. 

 The minute structure of the glands having been studied in those of the 

 scrotum, penis, or labia minora, which can be isolated without trouble, and 

 are, therefore, the best to begin with, — especially with the aid of acetic acid, 

 which renders the surrounding parts transparent — the investigation of those 

 of other parts, which concerns chiefly their form, size, and position, will be 

 most facilitated by the use of alkalies, especially caustic soda, which readily 

 clear up the tissues that obstruct the view of the glands ; whilst the latter, 

 in consequence of their fatty contents, are but little affected. Should it be 

 desired to study not so much the coverings as the cells of the glands, and, at 

 the same time, to obtain a general view of their form, there is no better plan 

 than to macerate the skin, after which the hairs with their root-sheaths, and 

 the cell-masses of the sebaceous glands, epithelium, and contents, may be 

 often stripped off in toto with the epidermis. The same end may be attained 

 more speedily where the epidermis is thin (scrotum, labia majora ', glans penis), 

 by dropping concentrated acetic acid upon it, or by means of soda, although 

 more of the cells of the glands are destroyed in this way. The maceration 

 of the foetal skin, and the rendering it transparent by acetic acid, are of great 

 use in studying its development. The fat-cells in the interior of the glands 

 are quite easily isolated by teasing out a good-sized gland. The excreted 

 secretion may be examined both by itself, and with the addition of water and 

 caustic soda. 



Literature. — See the treatises cited under the section on the skin ; of 

 Gurlt (p. 409), Krause (p. 126), G. Simon (p. 9), Valentin (p. 758). Also the 

 general histological works by Todd and Bowman (p.424, fig. 92), Sharpey, 

 Hassal (pi. liv. should be pi. liii., p. 401), Gerber (p. 75, figs. 40, 42, 43, 44, 45, 

 239), the drawings by Wagner (Icon. Phys., tab. xvi. fig. n, c.), Arnold 

 (Icon. Anatom. Fasc, ii. tab. xi. fig. 10), and Berres (tab. xxiv.), in addition, 

 G. Simon, in Mull. Arch., 1844, p. 1. 



Of the Muscular System. 



§ 76. To the muscular system belong all the transversely-striped 

 muscles, which, together with their accessory organs, the tendons 

 and fasciae, serve for the movement of the skeleton, the proper 

 organs of the senses and the skin. They are situate between the 

 skin aud the bones, and between the bones themselves ; and are so 

 associated and connected by common investments, that the whole 

 may be rightly regarded as constituting one system. 



§ 77. The proper elements of the muscles in question, still 

 perceptible to the naked eye, — the transversely -strip eel (animal or 



