202 SPECIAL HISTOLOGY. 



thickness of the walls, 0-002-0-003 ; of the epithelium, 0-006 ; of the 

 cavity, 0'004 0-01 of a line. Among the axillary glands some have 

 canals of 0-07-0-1, even 0-15 of a line, with walls 0-006 of a line in 

 thickness, without the epithelium, and half of which is formed by the 

 muscular layer ; others and in fact the largest glands, possess canals of 

 0*030-06, with walls of 0*004 of a line ; in the areola and the genitalia 

 also, the dimensions of the larger glands vary, though within narrower 

 limits. 



All the coils of the sudoriparous glands are penetrated by connec- 

 tive tissue, interspersed with fat-cells, which supports the vessels and 

 unites the separate convolutions of the tubes with one another ; some of 

 them have an external fibrous covering investing the whole coil (of com- 

 mon connective tissue with fusiform nuclei), which is particularly well 

 developed in those more isolated coils which are lodged in the subcuta- 

 neous cellular tissue (penis, axilla, &c.) 



68. Secretion of the Sudoriparous Glands. All the smaller sudori- 

 parous glands contain, as soon as any cavity is apparent in their canals, 

 which, however, is by no means always the case, nothing but a clear, 

 bright fluid, without any formed contents. In the axillary glands, on 

 the other hand, the contents abound in formed particles, and appear 

 either as a grayish, transparent, semi-fluid substance, with innumerable 

 fine, pale granules, and often with solitary nuclei ; or as a whitish-yellow 

 tolerably viscid matter, with a varying quantity of larger, opaque, 

 colorless, or yellow granules, nuclei and cells, similar to the epithelial 

 cells above described. That these cell contents, which, as I have found, 

 contain much protein and fat, differ considerably from the common 

 sweat, which is fluid and presents no formed elements, and probably 

 rather approximate to the sebaceous secretion of the skin, is evident, on 

 which account we might be induced to remove the glands of the axilla 

 from the class of sudoriparous glands, and to regard their secretion as 

 of a peculiar kind. These glands, however, sometimes afford a secre- 

 tion containing but few granules, or even nothing but fluid ; and among 

 the larger axillary glands smaller ones occur, which, so far as regards 

 their contents, exhibit many transitions, on the one hand into the large, 

 and on the other into common small glands.* If we further consider 



* [However true it may be that this secretion is sometimes fluid, and similar to that of 

 sudoriparous glands in other situations, this is the exception, and by no means the rule. 

 But it is not on account of their secretion, but mainly of their different structure, that these 

 glands have been separated from the common sudoriparous glands. They differ from them 

 by being united' into groups, and by their yellowish color. In size, too, they vary. Many 

 are 5 or 6 times larger: some attain the size of 2 lines in diameter. The groups can be 

 readily seen with the unassisted eye, if the adipose tissue adhering to a flap of skin from the 

 axilla be removed. They then appear as small granulations of a reddish or rosy tint, and 

 are soft and pulpy. The excretory ducts are not spirally wound as in the ordinary sudori- 

 parous glands. 



In the Negro these axillary glands as first pointed out by Prof. Horner (American Journal 



