Corns in a horse do not answer to those excrescences found upon the feet of man; being bruises, they consist of effusion in every instance. The effusion may either be of blood or of serum; blood constitutes the old and the new corn, serum gives rise to the sappy corn. The suppurative corn is an after-consequence of either of those just named; when the effusion has been so large as to defy absorption, a new action is started up--pus is secreted, and a suppurative corn is then created. [Illustration: THE SITUATION AND ASPECT OF AN OLD CORN UPON A LARGE, FLAT FOOT.] [Illustration: THE DEEPLY-SEATED AND SMALL, SCARLET SPOT WHICH DECLARES THE PRESENCE OF A NEW CORN. ] An old corn is the least serious, especially when it is easily cut away; it appears as a black mark upon the surface of the horny sole, and is little thought of when it can be speedily removed by the knife, because this shows the horse had a corn, but at present is free from such an annoyance. When, however, a superficial corn cannot be scooped out with the drawing-knife, but becomes brighter and brighter as more and more horn is cut away, till it assumes the scarlet aspect of a new corn, the matter is rather grave, because it denotes the horse to have had, and not to have been free from, corns during the growth of the present sole. The new corn, as has been just intimated, consists of a portion of blood effused into the pores of the horn, and is of a bright-scarlet color. The size is of some consequence, as it best intimates the extent of the injury; if the stain be small and deep seated, it is of least moment. The sappy corn is the consequence of a more gentle bruise, when serum and lymph only are effused--the horn being thereby merely rendered moist, not discolored. This species of corn is not very common, and by proper shoeing is readily removed. The suppurating corn is the worst of all; it engenders heat in the foot, and causes excessive lameness; it creates all that anguish, a shadowy taste of which the human being endures when pus is confined beneath the substance of the finger-nail. The foot cannot be put to the ground; the arteries of the pastern throb forcibly; the countenance is dejected; and every symptom of acute suffering in a large body is exhibited.