OF THE SKIN CUTANEOUS TRANSPIRATION. 



521 



182. 





subdivision (2), sometimes also giving off short crcoal processes before their 

 termination. These are seated rather beneath the Corium and in the midst 

 of the subcutaneous adipose tissue, than in the substance of the skin itself, 

 and the glomerulus is always invested by a sheath of smooth muscular tissue 

 (Krause). 1 The tubuli of each gland are lined throughout with a single 

 layer of columnar epithelium, and unite so as to form but one duct; and 

 this passes upwards through the Cutis and Cuticle, in a somewhat corkscivw- 

 like manner (3), to open upon the sur- 

 face of the latter (4), which it usually 

 reaches obliquely, so that the outer 

 layer of the Epidermis forms a sort of 

 little vaive. which is litted by the se- 

 creted fluid as it issues forth. These 

 glandulre are diffused in varying pro- 

 portions over the entire surface of the 

 body. According to Mr. Erasmus Wil- 

 son, 2 as many as 3528 of them exist in 

 a square inch of surface on the palm of 

 the hand ; and since every tube, when 

 straightened out, is about a quarter of 

 an inch in length, it follows that, in a 

 square inch of skin from the palm of the 

 hand, there exists a length of tube equal 

 to 882 inches, or 73J feet. The number 

 of gland ulse in other parts of the Skin 

 is sometimes greater, but is generally 

 less than this; and, according to Mr. 

 Wilson, about 2800 may be taken as the 

 average number of pores in each square 

 inch throughout the body. Now the 

 number of square inches of surface, in a 

 man of ordinary stature, is about 2500 ; 

 the total number of pores, therefore, may 

 be about seven millions; and the length 

 of the perspiratory tubing would thus be 

 1,570,000 inches, or nearly 28 miles, or 

 would represent a solid mass about equal 

 to one-third of a kidney (77 cub. cent., 

 Krause). 



420. Although a separation of fluid 

 by this extensive glandular apparatus is 

 continually taking place, yet this fluid, 

 being usually carried off in the form of 

 vapor as fast as it is separated, does not 

 ordinarily accumulate so as to become 

 sensible. If, however, from the increased 



amount of the Secretion, or from the COn- 

 ,. . . ,.' 



dition of the surrounding air as regards 

 temperature and moisture, the whole 



fluid thus poured out should not evapo- 



,, . , ,, . , ' 



rate, the residue forms minute drops 



upon the surface of the skin. Thus the Sudoriparous excretion may take 



Sudoriparous Gland from the palm of the 

 hand, magnified 40 diam.: 1, 1, contorted tubes, 

 composing the gland, and uniting in two ex- 

 cretory ducts, 2, 2, which unite into one spiral 

 canal that perforates the epidermis at c, and 

 opens on its surface at 4 ; the gland i , imbedded 

 in fat-vesicles, which are seen at 5, 5. 



1 Krause, Centralblatt f. d. Mc-cl. Wiss , 1878, p. 817. 



2 On the Management of the Skin, 3d edit., p. 37. 



34 



