10 'l^ilE BOTANICAL MAGAZINE. [Voi. xxn. No. 252. 



While these two specific organisms constitute the " Shiro- 

 koji " proper, and are necessary for its action, it contains also 

 some germs of such cosmopolitan species as Penicillium glaucum, 

 Oidium lactis, Aspergillus nidulans etc., which are merely 

 accessory or foreign organisms, doubtless due to the admixture 

 of spores from outside. 



(1) Rhizopus of the " Shiro-koji." 

 This mould grows very luxuriantl}^ upon such nutritive 

 culture-media as steamed rice, bread, gelatine. Agar-agar etc. 

 Thg culture produces a snowy, aerial mycelium and only a few 

 sporangia are visible here and there as black spots, scattered 

 over the whole mycelial mass. The walls of the sporangia are 

 coarsely granulated and their stalks are brownish yellow in 

 colour. 



The chlamydospores, however, are very abundantly produc- 

 ed, and are round or elliptic in shape, of refractile appearance, 

 filled up with finely granulated protoplasm, and tolerably 

 thick-walled. Zygospores have not yet been found. 



The vegetative hyphae are colourless (sometimes they con- 

 tain oil drops, yellowish in colour), variable in thickness, and 

 in contact with the substratum many conspicuous rhizoids are 

 formed . 



The optimum temperature for the growth is about 37°c. 

 The power of dissolving starch is very strong, but the liquifac- 

 tion of gelatine comes out very slowly. Cultivated in beer 

 wort or koji-decoction, there is produced a small amount of 

 alcohol.'^ Dextrose, maltose, soluble starch and mannite, on 

 the one hand, were found to be good carbon-sources, but 

 lactose, saccharose and glycerine less satisfactory. On the other 

 hand, pepton (witte), asparagin, ammonium nitrate and am- 

 monium tartarate may be used, and form good sources of 

 nitrogen. 



In form, size and general behaviour, this fungus agrees so 



1) The culture proihiceJ some gas-bubbles wilhiu the interstices of the grown 

 niyceiia. The presence of alcohol was recognised by the odour of distillate and 

 agjiin bv the iodoform test. 



