I yo AIDS TO BACTERIOLOGY 



water. Loffler's methylene blue stains the filaments of 

 the mycelium and hyphaB, the spores remaining unstained. 

 For permanent preparations moulds are mounted in 

 glycerin jelly, the cover-glass being ringed with varnish. 



Culture of Moulds. The moulds grow on nutrient 

 gelatin and agar, on potato and bread-paste. The best 

 media are glucose agaf, wort gelatin, and wort agar. 



Fermentation by Moulds. Some species of Mucor, 

 when immersed in a fermentable saccharine liquid, such 

 as wort, very quickly change their appearance: the 

 submerged hyphse swell irregularly, and a large number 

 of transverse septa appear, which divide them into barrel- 

 shaped or irregular cells, filled with highly refractive 

 plasma; these cells seem to multiply by budding, like 

 true yeast. If, then, the above-mentioned cells are 

 brought to the surface of the liquid, or otherwise under 

 aerobic conditions, they are again able to develop the 

 typical mould form. The most active fermentative power 

 is possessed by Mucor erectus, which in ordinary beer- 

 wort can be made to yield up to 8 per cent, by volume of 

 alcohol. Another form, the Mucor (amylomyces] Eouxii, 

 obtained from a Chinese rice fermentation, is used com- 

 mercially for the conversion of starch into alcohol. 



OVdiaeese. 



The Oidiacece are generally classed among the Hypho- 

 mycetes. No special spore- bearing organs are present, 

 but the hyphse bud at the extremities, forming spores. 



Oidium lactis, found in sour milk and butter as a white 

 fur, grows on gelatin without liquefaction, producing a 

 smell of sour milk. On agar it grows in the form of little 

 stars, which then overgrow the medium. In a stab 

 culture the fibres of the mycelia permeate the medium. 

 O. lactis grows very readily in milk, which it does not 

 change in any special way. It is not pathogenic to man 

 or animals. 



Cndium albicans grows on the mucous membrane of 

 the mouth and pharynx of children, producing thrush. If 

 one of the white patches be removed and teased up, the 

 filaments and yeast-like cells can be distinguished. It 

 does not flourish in an alkaline medium, but can be grown 

 on milk, bread, gelatin with liquefaction, agar, and potato. 

 On all these media it produces a very copious growth, 



