124 VETERINARY STATE BOARD 



perspire freely on the foot-pads and but very little elsewhere. 

 The sweating of pigs is confined to the snout. Sheep are said to 

 perspire very little or not at all. 



The sebaceous glands, racemose in type, are scattered quite gener- 

 ally over the body, but are more especially developed where there 

 is an abundant supply of hair, also in the prepuce, ears and eyelids. 

 The ducts of the sebaceous glands, as a rule, empty into the hair 

 follicles. These glands are very numerous in sheep and secrete 

 the oily substance known as wool-fat or lanolin. 



What is the difference between sebaceous and sudoriparous glands? 



Sebaceous glands are racemose in type; their secretion, sebum, 

 an oily substance, is formed principally by a fatty degeneration and 

 breaking down of the cell-content. 



Sudoriparous glands secrete sweat by a ti'ue secretory activity 

 of the cells composing them. The nerve supply to sweat-glands is 

 more acutely developed than is the case with sebaceous glands. This 

 is demonstrated by the effect of emotion on the production of sweat. 



What is sebum ? State where and how it is secreted and give its func- 

 tions. 



Sebum is the secretion of the sebaceous glands; it is a thick, 

 semifluid substance, composed of fat and epithelial debris from the 

 cells of the Malpighian layer. For manner of secretion, see answer 

 to preceding question. 



Sebum saves the epithelium from the disintegrating influence of 

 water, protects the animal from the elements, especially rain storms ; 

 keeps the skin moist and pliable and maintains a glossy hair coat. 



State the effect of a complete compulsory suppression of cutaneous 

 perspiration. 



A loss of body heat followed by death in a few days is produced 

 by varnishing the skin. Formerly, it was thought that this result 

 was due to the retention of poisonous products. 



Of what does dandruff consist? 



Epithelial scales, fat, coloring matters, salts, silica and dirt. 



State the difference in structure of hair, fur and wool. 



Fur is very fine, closely set hair, and is distinguished from 

 ordinary hair, which is longer and coarser and generally more or 

 less present with it. "Wool is a modified form of hair, distinguished 

 by its slender, soft and wavy or curly structure and by the highly 

 imbricated or serrated surface of its filaments. 



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