=IV. CELL GRANULES AND CELL INCLUSIONS.= The granules and cell-inclusions here included fall within the class of special protoplasmic structures found particularly in neoplasms and inflamed tissues, and which have been supposed to be parasites. For the staining of other cell-granules see Blood and Blood-forming organs. 1. =Altmann’s Granules.= 1. Fix small, thin pieces of fresh tissue in equal parts of 5 per cent potassium bichromate and 2 per cent perosmic acid for 24 hours. Wash in running water for several hours. After-harden in alcohol, and imbed in paraffin. Cut very thin and mount on cover-glass; remove paraffin. 2. Stain in aniline-water-acid-fuchsin (acid fuchsin 20 grms., aniline water 100 cc.), warming until vapor is given off. 3. When cool remove the fuchsin with a mixture of 1 part saturated alcoholic picric acid and 2 parts of water. 4. Renew the picric acid solution and warm on the paraffin oven for 30-60 seconds. 5. Dehydrate in alcohol; clear in xylol; mount in balsam. Protoplasm yellow: Altmann’s granules red: fat black. 2. =Russell’s Bodies.= 1. Fix and harden in Müller’s; wash; after-harden in alcohol; imbed in paraffin; mount on cover-glass. 2. Stain sections in a saturated solution of fuchsin in 2 per cent carbolic acid 10 minutes or longer. 3. Wash in water. 4. Wash in absolute alcohol for 30 seconds. 5. Counterstain in iodine green (1 grm. in 100 cc. of a 2 per cent carbolic acid) for 5 minutes. 6. Dehydrate quickly in absolute alcohol. 7. Clear in xylol; mount in balsam. Nuclei are green; Russell’s fuchsin-bodies light-red; Altmann’s granules light-red. 3. =Pianese’s Method.= 1. Fix in Pianese’s solution (see methods of fixation) 6 hours; wash in running water for 12 hours; after-harden in graded alcohols; imbed in paraffin; mount on cover-glass. 2. Stain 30 minutes in a staining mixture consisting of malachite green 0.5 grm., acid fuchsin 0.1 grm., Martius yellow 0.01 grm., distilled water 150 cc., 96 per cent alcohol 50 cc. 3. Dehydrate in absolute alcohol; clear in xylol; balsam. Nuclei are green; protoplasm reddish; cell-inclusions light-red. 4. =Method for Staining “Plimmer’s Bodies.”= 1. Fix in Hermann’s fluid for 12-24 hours. Imbed in paraffin. Mount sections on cover or slide. 2. Transfer sections to hydrogen peroxide for 15-30 seconds. 3. Wash in water. 4. Transfer to a 4 per cent ferric alum solution for 2 hours. 5. Wash in water. 6. Stain in 0.5 per cent watery hæmatoxylin solution for 30 minutes. Differentiate in the ferric alum solution until the nuclei are dark and protoplasm colorless; control under the microscope. 7. Wash in water 3-6 hours. 8. Counterstain in 1 per cent solution of Ehrlich’s neutral red until section is yellow-red.