584 THE DISEASES AND DISORDERS OP THE OX. 



but too frequently characteristic of the beginning of a febrile 

 disorder. 



The skin may be roughly divided into three parts. Of these 

 the most external is the cuticle^ that hard portion which is so 

 familar as that which is raised by the action of a blister. In 

 this layer there are small pores through which the hairs pass. 

 Next comes the rete raucosum, wherein the colouring-matter is 

 deposited. Most internally placed comes the cutis or true skin, 

 which contains nerves, blood-vessels, sebaceous and sudoriferous 

 glands, and bundles of connective tissue. The sebaceous glands 

 secrete an oily fluid, whereby that glossy look which is seen in 

 animals which are laying on flesh and doing well is imparted. 

 The sudoriferous or sweat-glands pour out the perspiration. 



Now we proceed to deal with the disorders to which the skin 

 is subject — first, those which are not parasitic, and then those 

 which depend upon the presence of parasitic organisms, whether 

 animal or vegetal. Speaking generally of them all, we may 

 say that one very great point in regard to treatment is that the 

 strictest cleanliness should be enjoined. 



ERYTHEMA. 



Simple erythema consists in a bright redness diff'used gene- 

 rally over the surface of the skin, and more or less regularly 

 exhibited. When pressure is applied, this redness disappears, 

 but it is soon renewed after the pressure is removed. 

 This affection is only rarely seen for many days as a simple 

 erythema except in parts affected by parasites. On the contrary, 

 in the general way erythema becomes complicated by the 

 formation of vesicles or even of pustules. An erythematous 

 skin may, in short, develop vesicles which may become confluent 

 and may exude a gelatinous sticky fluid whereby the hair on the 

 surface of the skin may be matted together. The vesicles may 

 become pustular, and the skin may ulcerate, and slough off in 

 parts. In some cases erythema remains simple, the cuticle is 

 shed, and the skin again becomes healthy. In the case of 

 patients which have died when suffering from simple erythema, 

 the redness can be seen to be confined to the outer layer of the 

 skin, as is shown if a transverse section be made, while the 

 deeper portion is not as a rule much affected. 



Now, simple erythema may become chronic, especially upon 



