70 MEDICAL MYCOLOGY 



of the preparation may speed up the reaction. Skin scrapings are also cleared 

 satisfactorily by this simple method. Henrici advocates a 25% solution of 

 antiformin, such as is used in digesting- tuberculous sputum, in place of the 

 sodium hydroxide solution. 



Stains for Sputum, Pus, etc. — Fungi may be found in sputum, pus, or 

 exudates by making mounts in 20% potassium hydroxide, or by smears. The 

 latter is not very satisfactory except for indicating the presence of mycelium 

 or cells, since smearing tends to disturb the arrangement of the cells. There 

 is usually a great amount of contamination unless one is able to open a fresh 

 lesion which shows no fistulae or draining sinuses. Where the latter are present, 

 biopsies are necessary to find the suspected fungi. Since in exudates the or- 

 ganisms may be few in number, it may require several examinations to locate 

 the parasite. The hydroxide tends to dissolve most of the tissue elements and 

 leave the fungi as refractile bodies. 



In potassium hydroxide preparations of scales from inflammatory lesions 

 Becker and Ritchie (1930) have indicated artefacts which rather closely re- 

 semble yeast cells. These bodies vary in shape from spherical to ellipsoidal 

 and have a highly refractive wall of varying thickness. Even appearances of 

 sprouting and septal formation occur. These may be removed by treating 

 material progressively with absolute alcohol, ether, absolute and 95% alcohol. 

 The appearances known as mosaic fungus, reported by Greenwood and Rock- 

 wood (1930) to be degenerate hyphal cells, is suggested by Becker and 

 Ritchie (1930) to be a result of inflammatory changes in the tissues. 



Vital Staining of Fungi. — Dalmau (1929, 1930) reports a technic of vital 

 staining which, while not original with her, deserves much wider use than it 

 receives at present. It is essentially similar to some of the blood stains. The 

 slides should be new, free from blemishes, and should be freed from fat by 

 the use of cleaning solution. After neutralizing, they should be cleaned with 

 a fat-free cloth. Immediately prior to use, all dust must be removed with a 

 new camel's hair brush, washed with ether, and dried. On one slide place 

 one or two drops of Janus green, neutral red or Scharlach R solutions (1 :2500) 

 in ethyl alcohol and let them extend over the entire slide, which they Avill do 

 if the latter is fat-free. Dry in the air. Place a drop of the liquid medium 

 containing the fungus upon a cover slip and invert upon the slide containing 

 the stain. Let settle and then rim the edges with vaseline. Examine at 

 intervals. 



Dalmau (1930) reports successful staining of fixed material with the com- 

 mon blood stains (Wright's, Giemsa, and Leishman). With a platinum loop 

 mix some of the colony with a drop of clear blood serum, placed at the end 

 of the slide. Before it dries spread it gently with another slide, thus produc- 

 ing a thin film. Fix with methyl alcohol from 1 to 3 minutes. Stain with the 

 above-mentioned blood stains and use neutral water for washing or diluting 

 the stain. The stain should remain from 5 to 15 minutes. Differentiate for a 

 few seconds only with acetic acid (1:1000). Wash wftll. The addition of 

 serum prevents undue shrinkage of the cells. 



