GLANDS. 105 



duct has no proper coat, this being replaced by the 

 epidermic cells which form its walls, but, in the thick- 

 ness of the skin, its walls are formed by two coats : 

 the outer, dense and fibrillated (2 o oth of a line in 

 thickness), including non-striated muscular fibres, 

 which, according to Kolliker, are also found in the 

 fibrous envelope of the glomerule ; the inner coat thin 

 (Wo <rth of a line), unorganized, and lined by an epi- 

 thelium similar to that of the gland (PL XIX. fig. V. ; 

 fig. VI). 



The ceruminous glands, which belong to the exter- 



nal ear. are identical in form with the sweat glands : 



. 



they differ from them only in the nature and arrange- 

 ment of their epithelial cells. Thus, instead of being 

 spread out in a simple layer upon the internal surface 

 of the secreting tube, their cells form a series of strata 

 by which its cavity is completely filled (PL XIX. fig. 

 VII. 2). Moreover they become infiltrated with 

 yellow pigment, and oil-globules in abundance, cha- 

 racteristics in which these glomerules, as regards their 

 secretion, resemble closely the sebaceous glands. The 

 large sudoriparous glands of the axillae seem to be 

 absolutely of the same species a# the ceruminous 

 glands, for their contents are identical. 



The sudoriparous glands are developed from the Development 

 fifth to the eighth month of foetal life. They make 

 their first appearance in the shape of minute cellular 

 projections from the deep surface of the epidermis, 

 which imbed themselves in the true skin. At first 

 they are nothing more than solid cylinders slightly 

 bulbous at their dermal extremities. As they grow, 

 they reach the deepest layer of the skin, but do not 



7 





