[Illustration: FIG. 124.--Bacillus and spirillum of Vincent, from case of ulcerative stomatitis. Stained (obj. one-twelfth oil-immersion; X1000) (Boston).] Vincent's angina is a chronic pseudomembranous and ulcerative inflammation of pharynx and tonsils. It is probably caused by two micro-organisms living in symbiosis--one a fusiform bacillus, the other a long spirillum (Fig. 124). They can readily be demonstrated in smears stained with Löffler's methylene-blue. The bacillus is spindle shaped, more or less pointed at the {274} ends, and about 6 to 12 µ long. The spirillum is a very slender, wavy thread, about 30 to 40 µ long. Tuberculous ulcerations of mouth and pharynx can generally be diagnosed from curetings made after careful cleansing of the surface. The curetings are well rubbed between slide and cover, and the smears thus made are dried, fixed, and stained for tubercle bacilli. Since there is much danger of contamination from tuberculous sputum, the presence of tubercle bacilli is significant only in proportion to the thoroughness with which the ulcer was cleansed. The diagnosis is certain when the bacilli are found within groups of cells which have not been disassociated in making the smears. THE EYE [Illustration: FIG. 125.--Conjunctival secretion from acute contagious conjunctivitis; polynuclear leukocytes with the bacillus of Weeks; P, phagocyte containing bacillus of Weeks (one-twelfth oil-immersion; ocular iii) (Morax).] _Staphylococci_, _pneumococci_, and _streptococci_ are probably the most common of the bacteria to be found in nonspecific conjunctivitis and keratitis. The usual cause of acute infectious conjunctivitis, especially in cities, seems to be the _Koch-Weeks bacillus_. This is a minute, slender rod, which lies within and between the pus-corpuscles (Fig. 125), and is negative to Gram's stain. In smears it cannot be {275} distinguished from the influenza bacillus, although its length is somewhat greater. The _diplobacillus of Morax and Axenfeld_ gives rise to an acute or chronic blepharo-conjunctivitis without follicles or membrane, for which zinc sulphate seems to be a specific. It is widely distributed geographically, and is common in many regions. The organism is a short, thick diplobacillus, is frequently intracellular, and is Gram-negative (Fig. 126). A delicate capsule can sometimes be made out. [Illustration: FIG. 126.--The diplobacillus of Morax and Axenfeld (from a preparation by Dr. Harold Gifford).] Early diagnosis of gonorrheal ophthalmia is extremely important, and can be made with certainty only by detection of _gonococci_ in the discharge. They are easily found in smears from untreated cases. After treatment is begun they soon disappear, even though the discharge continues.