These are fungi forms without chlorophyll, in which sexual reproduction takes place by conjugation, so that the mould are somewhat higher than the yeasts in the vegetable kingdom. The mould spore develops a much branched mycelium, which spreads over or through the nutrient matter in which the fungus grows. The mycelium sends up branches (hyphę) into the air, which develop rounded and enlarged ends: these are the spore-cases, or sporangia, containing new spores.

Certain of the moulds (Mucor, spp.) have in recent years become of considerable importance in the alcohol industry, owing to the fact that during the growth of the mycelium they secrete amylase (diastase), and also fermentation enzymes. Thus they can both saccharify starch and convert the sugar so formed into alcohol. Chiefly, however, they have been used as sources of diastase-activity in the saccharification of starchy mater'als, effecting in this way a considerable economy in malt. The fermentation is then completed by adding yeast.

Amylomyces Rouxii is a mucor which was isolate by Calmette

1 Allgem. Brau.-Hopf. Zeit., 1916, 56, 1547; J. Soc. C l. Ind. (Abst.), 1917, 36, 300. 2 Biochem. J., 1917, 11 II in the year 1892 from Chinese rice-ferment. Calmeste studied more especially its starch-saccharifying properties, but a few years later it was found (Boidin: Sanguinetti) that this organism could also convert sugars and dextrins into alcohol; and in 1898 it was used industrially for this purpose. It is from the A. Rouxii that the "amylo"-process of alcohol making took its name. The organism, however, was replaced later on by others which produced less acid.

Aspergillus oryzę, another of the moulds, was separated from the Japanese "koji" ferments used in making "saki"; and was applied practically by Takamine to the saccharification of rice. Its action, however, is too energetic.

Rhizopus oligosporus, R. Japonicus, and R. Delemar are other moulds which have been employed for saccharifying starch: their action resembles that of A. Rouxii.

Other mucors, viz. Mucor-β obtained from koji, and Mucor-γ from Tonkin rice, were subsequently isolated (Boidin, Collette, and Mousain), and having been found to produce less acid than A. Rouxii, have supplanted the latter. Mucor Boulard No. 5, introduced in 1912 by the Soc. Francaise des Distilleries de l'Indo-Chine, is claimed to be as strong a saccharifying agent as the mucors previously used industrially, and, in addition, to do its work in media containing active bacteria, so that there is no necessity to work under aseptic conditions.1