THE MOULD-FUNGI. 99 



sporangium-carrier like an umbrella, the line of junction 

 of the external wall remaining in evidence in the form of a 

 collar. 



The species of Mucor have, considered from one point of 

 view, very considerable interest, since they are able to act, 

 in different degrees, as true alcoholic ferments. As previously 

 mentioned, some of the species of Mucor,, when immersed in 

 a fermentable saccharine liquid, very quickly change their 

 appearance ; and whilst the mould thus approaches the yeast- 

 like fungi in its appearance, it at the same time causes an 

 actual alcoholic fermentation, yielding alcohol and carbonic 

 acid- as the chief products. If then the above-mentioned 

 free cells of the mould-fungus are brought to the surface of 

 the liquid by the bubbles of carbonic acid, they are able to 

 again develop the mould form. The power of bringing about 

 an alcoholic fermentation is possessed by the majority of the 

 species of Mucor, but in a different degree ; still the fermen- 

 tative power is not exclusively connected with the formation 

 of the above-mentioned budding gemmae, since these have 

 not been observed in Mucor Mucedo and stolonifer. 



According to the recent investigations of Hansen, the 

 various species, as far as they really are alcoholic ferments, 

 induce fermentation not only in solutions of dextrose and 

 invert-sugar, but also in solutions of maltose. Of all the 

 species which he investigated, Mucor racemosus is the only 

 one thai is capable of inverting a cane-sugar solution ; the 

 others are consequently unable to bring about fermentation 

 in a solution of this sugar. 



The most active fermentative power is possessed by Mucor 

 erectus. In beer-wort of ordinary concentration 14 to 15 

 Balling it yields up to 8 per cent, by volume of alcohol. It 

 also induces alcoholic fermentation in dextrin solutions, and 

 converts starch into reducing sugar. Mucor spinosus yielded 

 up to 5*5 per cent, by volume of alcohol in beer- wort. In 

 maltose solutions distinct fermentation phenomena were 

 observed, and at the end of eight months the liquid con- 



