In patients suffering from malaria the plas modium malariw may be found. The forms which the organism assumes are known as tertian, quartan, and iestivo-autimmal. They occur with in the red blood cells, rarely in the plasma. The recognition of the malarial parasite requires ex tremely careful technique and experience. For more detailed description of the parasite and of the methods used in the detection of the same the reader is referred to Delafield and Prudden's Handbook of Pathological Anatomy and Histol ogy, ed. 6, with references on page 259.
Free pigment is sometimes found in the blood. This condition is known as inelanremia.
Various foreign bodies such as fat, air, bac teria, animal parasites (distoma hcematobium, filaria sanguinis hominis, and the eggs of the trichina and echinococcus), endothelial cells, pus cells, tumor cells, etc., are sometimes found in the blood.
Examination of the blood in typhoid for the so called Vida) reaction should be mentioned. The blood or serum to be examined is mixed with ten times its amount of a twenty-four-hour-old broth culture of the typhoid bacillus and examined under the oil immersion lens. A positive reaction consists in the rendering motionless of the bacilli and their collection into groups. if a reaction with the one to ten dilution occurs, a one to twenty should be tried. Positive reaction with the one to twenty dilution makes the diagnosis of typhoid extremely probable. A negative result is of less value.
Stains may be examined to determine the presence or absence of blood, as follows. A drop of normal saline solution to which a few scrap ings from the stain have been added is evaporated on a glass slide. This is then covered and a drop of glacial acetic acid allowed to rim under the cover. The preparation is next heated until it bubbles. More acid is added and the slide heated until a brownish color appears. The specimen is then slowly dried and mounted in glycerin. If any blood was present it is shown by the presence of small crystals which result from the conversion of hemoglobin into hiemin.
Pieces nifty be examined by mixing a small amount with a drop of normal saline solution on a glass slide and covering with a. cover glass. Detritus from incomplete digestion of food forms a large part of normal feces. Thus it is com mon to find in a specimen of feces vegetable cells of various kinds. starch granules, muscle fibres from meat, fat globules, coagulated al bumins, etc. In addition to these there are usually found mucus and epithelial cells, and not infrequently crystals of calcium oxalate, calcium phosphate, calcium sulphate. the fatty acids,
triple phosphates, cholesterin. etc.
Epithelial cells in large numbers are frequently associated with intestinal catarrh, especially in chi Idren.
lied blood cells may be found in conditions as sociated with hemorrhage.
Pus cells are frequent in catarrhal inflamma tions of the bowels. They are more abundant when the inflammation is suppurative in char acter. In typhoid fever and other ulcerative con ditions, bits of an ulcer which has sloughed, or groups of epithelium with pus cells attached may be found in the fwees.
large variety of bacteria are present in normal faeces. Sonic of these gain entrance with the food; others are normal habitats of the gastrointestinal canal. Among these may be mentioned the Bacillus coli eommunis, Proteus vulgaris, Leptothrix, and the Bacillus lactis acrogenes. Under certain as yet little under stood conditions, it appears that some of these micro-organisms may assume pathological sig nificance.
The typhoid bacillus occurs in the stools of persons suffering from typhoid fever. As its appearance under the microscope is identical with that of the Bacillus soli communis, the two must be differentiated by biological methods.
Tubercle bacilli may be found in the faeces. (For method of staining, see TUBERCULOSIS.) occurring with pulmonary lesions and without intestinal symptoms, their source is usually in swallowed sputum. If, however, symptoms of enteritis are associated with tubercle bacilli in the stools, there is certainly a strong probability that the enteritis is tubercular.
The 'Comma' bacillus is present in the stools of persons suffering from Asiatic cholera.
The Amoeba coli is found in the faeces in amoebic colitis. It is best to examine stools for amteha as soon as possible after their passage and in the warm stage, as their motility is a valuable aid in its detection.
Sputum is examined microscopically to deter mine the character of the secretion of the respira tory tract. It may he examined by smearing on a cover glass or slide, fixing and staining with dilute aqueous solution of methylene blue. If there are little lumps of cheesy matter scattered through the sputum. it is well to select one of these from which to make the smear, especially if the tubercle bacillus is to be looked for. l'hot(igraphs of typical bacteria as (teen through the microscope are shim!' in the article D1sEASE, GERM THEORY OF.