124 SPECIAL HISTOLOGY. 



the fascia superficialis {bursa olecranii)^ or between the laminge of the 

 fascia muscularis {bursa patellar). The internal walls, smooth but un- 

 even, are formed of common connective tissue, possess no epithelium, 

 and include a somewhat viscid, clear fluid. 



The clastic tissue exists abundantly in almost all parts of the cutis ; 

 but, in general, far more sparingly than the connective tissue. More 

 rarely it occurs in the form of true elastic membranes, which may even 

 resemble the densest elastic networks of the arteries, as in the fascia 

 superficialis of the abdomen and thigh ; while more commonly it repre- 

 sents a loose reticulation of coarser or finer fibres, as in the corium. 

 The pctpilhe (but not all), and the pannicuhis acliposus, in which they 

 are sometimes wholly Avanting, contain only fine elastic (nucleus) fibre. 



1. Smooth muscles, according to my observations, occur far more exten- 

 sively in the skin than has hitherto been supposed, and particularly in 

 the subcutaneous cellular tissue of the scrotum, or the tunica dartos, 

 which has thence received the name of " muscular membrane" (Fleisch- 

 haut), and of the penis, including the prepuce and the anterior part 

 of its body, where they run in the form of yellow bundles (whose ele- 

 ments are figured in § 26), measuring |- to J a line, partly contiguous 

 to the vessels and nerves, partly more isolated in the connective tissue ; 

 they are sometimes converted into a network, but are more usually dis- 

 posed parallel to the raphe of the scrotum and the longitudinal axis 

 of the penis, though, more particularly in the latter situation, they not 

 unfrequently form large transverse bundles. 



2. In'the areola of the nipple, the smooth muscles, which are especially 

 well developed in the female, are disposed circularly in a delicate layer, 

 which becomes thicker internally towards the base of the nipple, and 

 are, for the most part, visible to the naked eye, on account of their 

 yellowish red color, and the thickness of their bundles (up to ^ of a line); 

 in the nipple itself they run in part circularly, in part perpendicularly, 

 and are united into a close network, through whose meshes the excretory 

 ducts of the lacteal glands pass. 



3. Lastly, smooth muscles are also found in the superficial portions 

 of the corium, and in fact in all situations where hairs occur, in the 

 form of flat bundles, 0-1-0-16 of a line broad, which, singly or in pairs, 

 are invariably placed near the upper part of the hair-follicles and seba- 

 ceous glands.* They arise, probably, from the superficial part of the 

 coriuvi, and running obliquely from without inwards, towards the hair- 

 follicles, surround the sebaceous glands, and are inserted close behind 

 and near the base of those glands into the hair-follicles. 



Quite recently Eylandt and Henle have added to our knowledge of 

 the smooth muscles of the skin. The existence of the little muscles of 



* [Smooth muscular fibres have also been foimd in the scalp. See note p. 104. — DaC] 



