With the advance of the inflammation the redness of the mucosa extends, at first in points and circumscribed patches, and later over the entire surface. The epithelium drying and degenerating in its surface layers forms with the mucus a sticky gummy film on the surface, which, mingling with decomposing alimentary matters gives out a heavy, offensive or even fœtid odor. The different parts of the mouth are now tender to the touch, and this, with the fœtor and even bitterness of the bacterial products combine with the general systemic disturbance in impairing or abolishing appetite. In any case mastication becomes slow and infrequent, and morsels of food are the more likely to be retained, to aggravate the local condition by their decomposition. The dry stage is followed by the period of hypersecretion, and in this the salivary glands take a prominent part, so that ptyalism (slobbering) becomes the most marked feature of the disease. The saliva mixed with the increasing secretion of mucus and the abundance of proliferating and shedding epithelium, escapes from the lips and falls in stringy masses in the manger and front of the stall. When there is much motion of the jaws and tongue it accumulates as a froth around the lips. A careful examination of the mucosa will sometimes detect slight conical elevations with red areolæ, representing the tumefied orifices of the obstructed mucous follicles, and later these may show as minute erosions. Even vesicles have been noticed (Weber, Dieckerhoff, Kosters), but when these are present one should carefully exclude the specific stomatites such as horsepox, contagious pustular stomatitis, aphthous fever, etc. Erosions of the mucosa and desquamation of the epithelium have been noticed in horses fed on purple (hybrid) clover, buckwheat or ergot, and in some of these cases the inflammation has extended (in white faces especially) to the skin of the face, the mucosa of the nose, and the adjacent glands, and as complications icterus, constipation, colics, polyuria, albuminuria and paresis of the hind limbs have been observed. These latter are common symptoms of cryptogamic poisoning. _Prognosis._ In uncomplicated cases the disease is not a grave one, lasting only during the continued application of the local irritant, and recovering more or less speedily when that has been removed. Complications are dangerous only when due to some specific disease poison (glanders, actinomycosis, strangles, etc.), and even poisoning by the usual cryptogams of leafy or musty plants is rarely persistent in its effects. _Treatment._ This resolves itself into the removal of the irritant cause and the soothing of the irritation. When the cause has been definitely ascertained the first step is easy.