606 



MANUAL OF HISTOLOGY. 



Fig. 567. Sudorific glflnd from the human being, a, con- 

 voluted portion surrounded by the radicals of venous 

 vessels; c, basket-like plexus of capillaries from around a 

 convolution, with arterial twigs; 6, excretory duct. 



gonal gland-cells of rather small size, ranging from 0'0113 to 0-0157 mm. 

 in diameter, and containing in their interior, as a rule, molecules of a 

 brownish pigment and of neutral fats. 



The space in the axis of the tube is filled either with a more or less 



transparent fluid, destitute 

 of granular matter, or, as is 

 the case with the larger 

 convoluted glands, with a 

 thickish matter, rich in 

 molecules of fats and albu- 

 minous substances, which 

 has its source in a bursting 

 of the gland-cells, and in 

 some instances nearly re- 

 sembles the fatty secretions 

 of the allied ceruminous 

 glands of the ear or race- 

 mose sebaceous follicles. 

 The blood-vessels are dis- 

 posed around the convolu- 

 tions of these organs in 

 delicate basket-like capil- 

 lary networks, c, c. Apart 

 from a dense network of 

 nerves surrounding the 

 capillaries of the sudorific glands (Tomsa), no special secretory nerves are 

 known for the organ, although the agency of the nervous system in the 

 mechanism of absorption is very probable. 



Sudorific glands occur over the whole surface of the human skin 

 whether covered with, hair or no, with the exception of a few limited 

 spots. They are liable, however, to vary considerably, both in regard to 

 grouping, size, and number, in different localities. On the ridges of skin 

 in the palm of the hand and sole of the foot they are arranged with 

 regularity in rows. It is most usual, however, to find them in small 

 irregular groups, separated from one another by small tracts of skin quite 

 free of glands. On the lip they extend as far as the red edge, and on 

 the nose to the entrance of the nostrils ; on the penis, again, as far as the 

 border of the external skin of the prepuce ; and on the pudenda to the 

 limits of the outer integument. Over the whole body almost, the smaller 

 species of glands alone present themselves, while the large tubules of 

 more complex constitution appear in the axilla only, crowded together 

 and forming a regular stratum. We are indebted to Krause for some 

 very interesting calculations in regard to the number of the sudorific 

 glands in different localities. Whilst on the back of the neck, back, and 

 nates, 417 on an average may be found in n"> the cheeks, for instance, 

 have 548 ; the inner surface of the thigh and leg, 576 ; the forearm 

 externally, 1093, internally, 1123; the breast and belly, 1136 ; the fore- 

 head, 1258; the dorsum of the hand, 1490; the palm, 2736; and the 

 sole of the foot, 2685. Thus, computing for the whole surface of the 

 body, this observer estimates the total number of these glands at 

 2,381,248. No doubt this is subject to great variation, according to the 

 individual. The mode of origin of the glandulae sudoriferae has been 

 referred to before at p. 360. 



