THE MOULD-FUNGI. 105 



it is true, Brefeld has discovered, in several higher fungi, a 

 formation of conidia resembling chains of Oidium cells ; but 

 it has not yet been determined whether this also includes 

 that particular species which we designate Oidium lactis. 



Fresenius correctly gave to this species the specific name 

 lactis (of milk) ; for universal experience goes to show that it 

 has its ordinary place of abode in milk, where it can in the 

 majority of cases be found. Up to now, however, no evidence 

 has been brought forward that this mould-fungus stands in 

 causal relation to the acid fermentations of milk. Further, it 

 occurs spontaneously in various other liquids, and among these 

 in -the saccharine mixtures which find employment in the 

 fermentation industries, and in these it is able to induce a 

 feeble alcoholic fermentation. 



The often forked, branched, thin-walled, transparent hyphse 

 (1) form a thick white felt; in the uppermost portions of the 

 filaments transverse septa are formed close together, after which 

 the single cells, filled with very refractive plasma, become 

 detached as conidia (3 to 7, 11 to 14, 17 to 19). When the 

 fungus grows on solid substrata, the hyphae unite and form 

 remarkable conical bodies. As a rule, the conidia in longitu- 

 dinal section are rectangular with rounded corners (3, 6, 1 7 to 

 19); in a growth of this mould-fungus, spherical, roundish, pear- 

 shaped, and quite irregular conidia (4, 5, 1 1 to 14) are, however, 

 also nearly always found. These organs of multiplication, the 

 only ones known, send out one or more germ-tubes. The 

 fungus may occur in beer, especially when poor in alcohol. 

 As the amount of alcohol increases, the conditions for its 

 growth become more unfavourable ; still, neither wort nor 

 beer is exposed to the danger of being attacked to any 



have developed ; after 9 hours (6'") these have formed transverse septa 

 and the first indications of branchings ; 11 14, abnormal forms ; 15, 16, 

 hyphse with interstitial cells, filled with plasma ; 17, chain of germinating 

 conidia ; 18, conidia which have lain for some time in a sugar-solution ; 

 the contents show globules of oil ; 19, old conidia. 



