GENERAL STRUCTURE. 33 



ceedingly thick on the pads of the feet and on the ventral 

 neck region, where, in contest with an enemy, it is most 

 likely to be seized. A fibrous connective tissue binds the 

 skin to the subjacent structures. In some places the 

 union is very firm, as on the distal parts of the limbs 

 and the head, while in other regions it is loose, as on 

 the lateral aspect of the trunk. 



The skin consists of an external layer, the epidermis, 

 and, beneath this, the dermis or true skin, designated the 

 corium. The epidermis is composed of numerous strata 

 of epithelial cells. Those on or near the surface are 

 much flattened while the deeper ones are more or less 

 cubical. As the superficial layer desquamates in minute 

 fragments, forming what is commonly called dandruff, 

 it is replaced by cells developed from the deeper layers. 



The portion of the epidermis adjacent to the corium 

 or cutis vera contains the coloring-matter of the skin, 

 and is known as the rete mucosum. At the orifices of 

 the internal passages, such as the digestive and genital 

 tracts, the epithelium changes to a soft delicate nature, 

 and is then known throughout these passages as mucous 

 membrane. 



The corium or dermis is a form of fibrous connective 

 tissue whose deepest portion forms the white fluffy 

 areolar substance cut in removing the skin. In many 

 regions just below the true skin is a layer of adipose 

 tissue, which when examined under the microscope is 

 seen to be composed of numerous globular fat-cells sup- 

 ported by fibrous areolar tissue. The seven pads on the 

 forepaw and the five on the hind one consist of greatly 

 thickened epidermis, the corium, and masses of fibrous 

 connective tissue enveloping many fat-cells. 



The sebaceous or oil glands lie in the corium, and by 

 means of a duct open into the hair follicle near the sur- 

 3 



