PHYSIOLOGY AND CHEMISTRY. 395 



vessel at first, whereas other species of the same sub-group re- 

 produce at once and very rapidly, as films on the surface. 



The production of a film occurs sooner or later with all the 

 species hitherto examined by myself. Several of them, chiefly 

 from the first sub-group, cover even alcoholic nutrient liquids 

 with a film by the end of twenty-four hours, and develop, like 

 Mycoderma, principally on the surface. The external similarity 

 to Mycoderma species is the greater when the dry, dull grey 

 films assume, like the latter, mesenteric folds in the course of 

 further development. In certain cases the film remains smooth 

 and delicate. The production of film vegetation takes a long 

 time with some species, and occasionally nothing more than a 

 ring is formed (see p. 120, vol. ii.), even at high temperatures. 

 The films then exhibit a moist gloss, resembling that of Saccharo- 

 mycetes, and are occasionally of a thick, mucinous character. 

 Strongly developed films may become coloured (lemon-yellow, 

 rose-red, leather-brown, olive-green). 



During development in nutrient liquids, a variety of pheno- 

 mena characteristic of the species are observed. A cloudiness 

 may set in at first, to subsequently disappear with the formation 

 of pulverulent, flocculent, agglomerate, yeasty, solid or muci- 

 nous, ropy sediments ; or, as in the case of Sacch. lactis, the 

 cloudiness may persist. In other instances the liquid remains 

 perfectly limpid. Two species impart a decided lemon-yellow 

 colour to saccharine yeast water. Other nutrient liquids, such as 

 beer wort and must (see p. 224, vol. ii.), are decolorised to a greater 

 or smaller extent. This has been established in the case of beer 

 wort by L. VAN DEN HULLE and H. VAN LAER (II.), WILL (XXXI.) 

 and P. LINDNER (XXXVII.) ; and for must by R. MEISSNER(H.). 

 In Will's experiments, the highest degree of decoloration, deter- 

 mined by the method of C. J. LINTNER (II.), was 0.6. Many 

 Torula species, on the other hand, seem to darken the colour of 

 beer wort, but whether this also applies to the Torula Novce Carls- 

 bergiw of GRONLUND (II.). must remain an open question owing 

 to the unreliable method of colour determination employed by 

 that worker. v^ 



The capacity of many Torula species for acclimatisation' in 

 highly concentrated nutrient liquids (see p. 229, vol. ii.), seems to 

 be very extensive. Thus the writer found one species able to 

 develop and produce a fairly brisk fermentation in a 76 per cent, 

 malt extract. Wehmer's salt yeast remained capable of develop- 

 ment for several months in herring pickle, representing a 24 per 

 cent, solution of salt, whereas Lactomyces inflans caseigrana, 

 Bochicchio, could not stand saturated solutions of salt for more 

 than 30-40 minutes. An addition of 15 per cent, of common 

 salt to the nutrient solution merely retarded the development of 

 the salt yeast in question. 



Acid nutrient solutions fairly strong, e.g., sauerkraut water 



