292 MAKUAL OF IIOPERN FARRIERY, 



some astringent mixed with the water, such as a small 

 portion of vinegar. 



The skin of the heel has numerous glandular pores, 

 through wliich the unctuous secretion oozes ; and sometimes 

 these are undulv excited, and this matter becomes altered 

 in its substance and odour, and produces that disease called 

 grease, described at page 144, and which in some instances 

 proves somewhat difficult to cure. 



The cutis, when destroyed by anj means, does not 

 regenerate quickly. . Great care should therefore be taken 

 not to allow any portion of it to be broken. ]\Iany think 

 that it is of little consequence for horses to have the skin 

 of their back rubbed off by friction from a saddle. Such 

 parts as have lost their cutis have it but slowly reproduced ; 

 and even when it has been restored, its vital power is 

 much weaker than it originally was ; for, although it ap- 

 pears at first to be very vascular, its vessels after a time 

 either shrink in calibre, or some of them become altogether 

 obliterated It invariably happens that when horses have 

 had fistulas or saddle-galls, they are always more disposed 

 to subsequent injury in those parts. 



THE RETE MUCOSUM. 



The third part of the skin consists of a membrane which 

 bears this name ; it is a fine, delicate, laminated tissue, 

 interposed between • the cutis and the cuticle. The skin 

 takes its colour from this membrane. It is from this mem- 

 brane being black in the negro that he takes his dark 

 colour ; for dissection has proved that his cuticle when 

 separated from this membrane is as white as that of a 

 European. Its use appears to afibrd protection to the 

 delicate vessels of the nerves from outward injuries. 



