FILAMENTOUS AND BUDDING FUNGI. 339 



bacteria. The filamentous fungi, with the exception of the 

 streptoth rices, which behave exactly as do bacteria with 

 regard to stains, do not stain well in general, although they 

 can be demonstrated with the aid of Loffler's methylene- 

 blue. Generally, it is preferable to examine these fungi 

 unstained. The filamentous fungi do not take up water, so 

 that they are generally mounted in glycerin. It is advisa- 

 ble to undertake the demonstration of teased preparations 

 from fungous vegetations in 50 per cent, alcohol containing 

 a few drops of ammonia, in order to avoid the disturbing 

 influence of air-bubbles ; or the teased preparations are 

 made in Unna's solution : gelatin I, alcohol 25, solution of 

 ammonia 25, glycerin 25, water 35. The following recom- 

 mendation of Unna is useful : The cover-slip preparations 

 are placed for a minute in 5 per cent, potassium hydroxid ; 

 then, after rinsing in water for five minutes, in 5 per cent, 

 acetic acid ; and finally they are exposed to the action of a 

 strong aniline stain (for instance, gentian-violet), possibly 

 under the influence of heat. Yeast is best stained with a 

 dilute aqueous solution of vesuvin, as the other aniline 

 dyes readily give rise to overstating. 



The cultivation of molds and budding fungi is carried out 

 in the same way as that of bacteria. Isolation is effected 

 by means of the plate -procedure, preferably with acid gela- 

 tin or agar (the gelatin or the agar is dissolved in acid 

 fruit-decoctions, beer-wort, or potato- water (p. 81) ), instead 

 of alkaline bouillon. For further cultivation bread-pap is 

 well adapted (p. 86). 



PATHOGENIC ACTIVITY OF FILAMENTOUS AND BUDDING 

 FUNGI FOR ANIMALS. 



Although the majority of filamentous and budding fungi 

 vegetate only upon dead organic material, a small number 

 of varieties may flourish in the animal body and thus give 

 rise to disease. A special position is occupied by the 

 streptothrices, the most important representative of which, 

 the streptothrix actinomyces (p. 354), will be fully con- 

 sidered. The best known among the remaining pathogenic 

 filamentous fungi are the aspergillus fumigatus and fla- 

 vescens, and the mucor corymbifer and rhizopodiformis. If 

 an emulsion of these fungi in bouillon is injected into the 



