2. Place the sections in a staining dish containing a measured amount of distilled water. To each cc. of water add one drop of Giemsa’s stain. Use clean glass-needles to manipulate the sections. After 1 hour transfer sections to a fresh solution, in which they are left 5-12-24 hours. 3. Wash quickly in a concentrated solution of potassium alum, then quickly in water. 4. Mount in glycerin-gelatin; or dry on the slide until nearly perfectly dry, then xylol, and balsam, or cedar oil. Alcohol must not be used. II. THE STAINING OF PATHOGENIC YEASTS AND MOULDS IN SECTIONS. 1. =Blastomycetes.= The parasites of blastomycetic dermatitis can be demonstrated unstained in pus treated with a weak sodium hydroxide. In sections they are easily found after treatment with ordinary staining methods. The various modifications of the Romanowsky method, or other methylene-blue-eosin staining, give better staining of the parasite than can be obtained by hæmatoxylin and eosin. 2. =Oïdium Albicans.= Staining with Weigert-Gram’s and lithium-carmine gives beautiful preparations. 3. =Moulds.= These are best examined in the unstained condition, by treating the material with equal parts of alcohol and ether, followed by a 3 per cent potassium hydroxide solution. The organisms and spores are brought out distinctly. Löffler’s methylene-blue may be used for staining. In the case of sections stain 1-2 hours and contrast with eosin. For the examination of hairs or horny scales for fungi, _Unna’s method_ may be used:— 1. Add glacial acetic acid to hair or epidermis; make cover-glass preparations, drying by heat. 2. Ether and alcohol equal parts. 3. Stain in borax 1 grm., methylene-blue 1 grm., water 100 cc., ½-5 minutes. 4. Wash in water; dry; balsam. If the horny elements are too deeply stained, decolorize in 1 per cent acetic for 10 seconds, or in 1 per cent oxalic, citric, or arsenious acid for 1 minute. III. THE STAINING OF ANIMAL PARASITES. 1. =Amoeba Coli.= Examine fresh material from fæces, abscesses or cultures, in physiologic saline solution, on a warm stage. Stain under the cover with methylene-blue and carmine. Make permanent mounts by removing excess of stain and running in 50 per cent glycerin. In fixed preparations the nuclei of the amoebæ do not stain with ordinary nuclear stains. _Mallory’s method_ may be used:— 1. Fix in alcohol. 2. Stain sections in a saturated aqueous solution of thionin 3-5 minutes. 3. Differentiate in a 2 per cent aqueous solution of oxalic acid for ½-1 minute. 4. Wash in water; dehydrate in absolute alcohol; clear in xylol; mount in xylol-balsam. Nuclei of the amœbæ and granules of the mast-cells are brownish-red; nuclei of cells blue.