Tumors and other pathologic specimens received from the surgeon should be fully described as to _size_, _form_, _weight_, _consistence_, _color_, _relation to surrounding tissues_ (encapsulated, well-defined borders, growth by infiltration or expansion, zone of inflammation, etc.), _character of cut-surface_ (color, moisture, translucency, smooth or elevated, homogeneous, character of cell-scraping, evidences of structure, etc.). Accompanying all pathologic material sent to the pathologist should be concise and accurate notes giving the name, sex, age, nationality, occupation and status of the patient, anything in the individual or family history bearing upon the condition, the source of the specimen, its exact location and relations, manner of growth and character of operation. The pathologist should have full data upon which to construct his diagnosis. A very common idea among surgeons is that the specimen alone should be sufficient for the pathologist, and that other data are not necessary for the formation of his opinion. Many other considerations than the mere histologic picture presented by a specimen enter into the formulation of a pathologic diagnosis, if it is to bring to the aid of the surgeon all that a pathologist’s knowledge and experience can give. This is particularly true when the pathologist, as is usually the case, is asked to give a prognosis. Both in hospital service and in private surgical practice it is best to have printed history forms to be filled out and to be sent to the pathologist with each specimen. Another factor seriously interfering with the efficiency of the pathologist’s work is the failure of the surgeon to see that the material removed for diagnosis is properly taken care of before it reaches the pathologist. Tissues removed for examination should never be allowed to dry. They should not be exposed to the air, but should either be placed at once in a fixing fluid or covered with damp cloth. Curettings should be placed for a moment upon a pad of gauze to remove the excess of blood, and the fragments of tissue are then picked up and put into the fixing solution. When sent by mail or express fresh tissues should be wrapped in damp cloth and then in rubber cloth; or if the distance is great they should be put into fixing fluids. A sufficient quantity of the latter should be used, or decomposition may take place before the specimen reaches the pathologist. All material for bacteriologic examination should be removed under proper precautions, put into sterilized vessels, properly sealed and sent to the pathologist under proper precautions. PART II. THE TREATMENT OF THE MATERIAL.