The first stage lasts for a period varying from a few hours to several days, and is followed by the stage of exudation. This is characterized by a free watery or mucoid discharge from the nasal chambers, and by the cessation of the symptoms due directly or indirectly to pressure of the layers of swollen mucous membrane against each other. The discharge at first is watery, and is doubtless composed of transuded liquor sanguinis. It is followed by a mucoid fluid, which in severe or neglected cases may assume a purulent character. In many instances, even in mild cases, the discharge becomes muco-purulent toward recovery. The second stage is associated in children and adults of delicate constitution with excoriations of the nostrils. Suppuration may take place in nurslings and in old people. It would appear that in coryza, as it exists in the northern countries of Europe, the beginning of the second stage is apt to be marked by free suppuration. Acute coryza may involve the sinuses of the face, particularly the maxillary sinus. The involvement of the frontal and sphenoidal sinuses, while possible, is infrequent. Pharyngitis, laryngitis, and occasionally acute aural catarrh, often coexist with the disease. The symptoms of coryza are so distinctive that the diagnosis is easily made. But since any obstructive or catarrhal state of the nose is described by patients as a cold in the head, it is necessary for the medical attendant to distinguish the various diseases so denominated. Acute coryza may be confounded with angiose hypertrophy; with the obstruction to nasal respiration due to deflection of the nasal septum or to an inflamed soft polypus; with catarrhal irritation affecting surfaces which are already enlarged by hyperplasia or which are undergoing atrophy; or with the effects of operative interference in the nose.