MICROSCOPY. 457 MICKOSCOPY. liroJucing casts of the tubules. From here they are washed along the urinary tubules into the irine. Casts almost clear composed of albumin and a few tine granules are known as hj-aline easts. Occurring in small numbers hyaline casts may be of little significance, being present in functional albuminuria in the urine of old per- CAST8. (at Hyaline; (i) was.v ; (f) li.T aline and frranular; (d) h.valine and epithelial ; (e) hyaline and blood; (_/") h.valine and pus. sons and often in urine otherwise normal. In chronic inflammation of the kidney these casts occur in large numbers. So-called 'waxy' casts are less transparent than the hyaline and turn brown when subjected to the action of iodine. They are characteristic of the waxy degeneration CRYSTALS OF CYSTIN. of the kidney which sometimes accompanies chronic nephritis. Casts containing epithelial cells are known as epithelial casts. They are associated with acute disease of the kidney. Blood casts, or casts containing red blood cells, are found in urine in cases of acute exudative ne- CABTS. (a) Fine granular ; (b) coarse granular ; (c) epithelial ; (rf) blood: (e)pus; (f) fatty. phritis and in connection with the hemorrhages which sometimes occxir. Pus casts, or casts con- taining pus cells, are found in suppurative ne- phritis and in some of the more severe cases of acute nephritis. Casts containing fine or coarse granules are of frequent occurrence. Pus cells are found in the urine in the more se- vere forms of acute nephritis and in suppurative inflammation of any part of the genito-urinary tract. Pus is most abundant in cystitis; less abundant and more thorougbl}- mixed with the urine in pyelitis ; least abundant, and confined mainly to the first part of the specimen passed, in urethritis. Kcd blood cells appear as round biconcave disks, about seven mieromillimeters in diameter. They HUMAN SPERMATOZOA GREATLY MAGNIFIED. (a) View of broad surface ; (6) view in profile. may be found in severe acute inflammations of the genito-urinary tract and in conditions deter- mining hemorrhage along the tract. Spermatozoa are frequently found in the urine of healthy individuals. Constant presence of spermatozoa in the urine may occur in certain diseases of the prostate and seminal vesicles. The condition is also frequently present in sexual neuro.ses. Yeast and mold plants are frequentl.v found in the urine of diabetics, more rarely in other conditions. Bacteria. Normal urine in the normal blad- der contains no bacteria. Non-pathogenic bac- teria are, however, frequentl.v added to the urine from the urethra or from the external genitals. Of these the Micrococcus urea> is one of the most common. The smegma bacillus is also sometimes present in large numbers and is important from the similarity which it bears to the tubercle bacillus as regards its staining qualities. Of pathogenic bacteria found in urinary sediments ma.v be mentioned the Staphylococcus pyogenes, Streptococcus p,vogenes, the colon bacillus, tu- bercle bacillus, and gonococcus. In such infec- tious diseases as septiciemia, pya'mia, erysipelas, diphtheria, and tuberculosis the specific germ of the disease is sometimes found in the urine. For descriptions of the appearance which these dif- ferent germs present under the microscope the reader is referred to the special articles on the diseases which the.v cause. For a description of the staphylococcus and streptococcus the reader is referred to the article on Bactehia. In ex- amining urinary sediment for bacteria, a small amount of the sediment is taken up with a plati- num loop and smeared on a cover glass in a thin layer. This is allowed to dry. To fix the
