EREMASCACEAE IMPERFECTAE 187 



never be fixed by heat. A smear may be allowed to evaporate the excess water 

 in air, then it should be fixed rapidly in alcohol and stained. Burri's India 

 ink method and Mitsche & Harrison's collargol methods are useful. Since 

 smears usually separate the cells of the filaments, they should be avoided as 

 far as possible and the morphology compared with that obtained in hanging 

 drops, using either liquid media or media containing 0.1% agar. Langeron & 

 Talice suggest a very thin slant of agar, which is streaked all the way to the 

 glass of the tube. For microscopic observation it is held as desired with two 

 lumps of modeling clay on the stage and observed with an 8 mm. objective 

 and an ocular of high magnification. In giant colonies, one must resort to 

 one of the various devices for growing them, so that they may be uncovered 

 for examination. These often give valuable morphologic details. Microcul- 

 tures from hanging blocks of agar are useful. On liquid media, a little of the 

 bottom deposit is lifted by a wide-mouthed pipette, and floated on a drop of 

 liquid on the slide. The excess liquid is removed by blotting or by evapora- 

 tion. It may be stained by the above-mentioned Lugol or by other suitable 

 stains. Hanging drop cultures of dilute potato decoction should also be made. 

 Here, after development has reached a suitable stage, the organism may be 

 allowed to dry to the cover glass and stained if desired. It may be desirable 

 to remove the lanolin which sealed the cover glass to the ring by wiping first 

 with a dry cloth and then with a cloth moistened with toluene. 



Pigment formation should be noted. It is quite variable, depending on 

 the composition of the medium, its density, the age of the culture, tempera- 

 ture, light, etc. 



Fermentation should next be studied. Unfortunately, Castellani has em- 

 phasized this to the exclusion of other characters, while others have failed to 

 confirm his results with many strains, perhaps on account of the method used. 

 Redaelli & Ciferri suggest the following list: arabinose, xylose, rhamnose, 

 glucose, mannose, galactose, fructose, sorbite, dulcite, maltose, lactose, meli- 

 biose, sucrose, trehalose, raffinose, starch, soluble dextrin, glycogen, and inulin. 

 However, see remarks on Monilia Castellani, pp. 63, 64. The use of Lendner's 

 microfermentation method is inadequate, unless all doubtful cases are studied 

 more quantitatively. Experiments should be controlled carefully and repeated 

 three or four times. The constancy of fermentative power has been ques- 

 tioned (Bahr 1915), probably as a result of too great reliance on Lendner's 

 method (see p. 63). While occasional cultures on a sugar which the fungus 

 does not ferment will not alter its ability, repeated subcultures on that sugar 

 may induce an irregular increase of abilitj'- to ferment that sugar Avhich is 

 gradually but irregularly lost when again cultivated on the first medium. 

 Mackie & Chitre (1928), in a study of the intestinal Moniliae of India associ- 

 ated with sprue, show that many strains lose their ability to ferment certain 

 sugars in subcultures on laboratory media and may regain this ability on pas- 

 sage through experimental animals. Ability or nonability to ferment maltose 

 was much more constant than that for any other sugars and may be used as a 



