SWEAT-GLANDS 



193 



epithelium, which, taken together, constitute but a very 

 thin pellicle ; and the arrangement, though different in 

 detail, is similar in principle to that which obtains in the 

 kidney. In the latter, the vessel makes a coil within the 

 Malpighian capsule, which ends a tubule. Here the 

 perspiratory tubule coils about, and among, the vessels. 



Pio. 58.— Coiled End of a Sweat-Gland (Fig. 57, gl.), Epithblium 



NOT SHOWN. 



a, the coil ; 6, the duct ; c, network of capillaries, inside which the 

 gland lies. 



In both cases the same result is arrived at, — namely, the 

 exposure of the blood to a large, relatively free, surface, 

 on to which certain of its contents transude. In the 

 sweat-gland however there is no filtering apparatus like 

 the Malpighian corpuscle of the kidney, and the whole of 

 the sweat appears to be secreted into the interior of the tube 

 by the action of the epithelium cells which line it. 



