212 PLANT LIFE. 



but there are some which have become parasitic. A 

 few species of Mucor and Aspergillus produce danger- 

 ous diseases in the lungs and bronchiae. A very 

 interesting series of fungi has been discovered in Java 

 and Japan. These are able to change rice starch into 

 sugar, and also to change the sugar into alcohol So 

 that the fungus or series of fungi really carries on by 

 itself the whole work of a distillery. 



Mucor belongs to the class of Algal fungi which 

 form spores by conjugation. The method closely 

 resembles that of Spirogyra and other Algae. The 

 other two fungi {Eurotiuin and P enicilliuni) are 

 Ascomycete fungi, and form, besides conidia, a sort of 

 sexual fertilisation which results in the production of 

 a peculiar round mass of cells, called the cleistocarp^ 

 within which are the asci and spores. As these fungi 

 are exhaustively treated in all books on botany, it is 

 unnecessary to describe their spore formations in detail. 



The Yeasts are another very important group of fungi 

 belonging to the Ascomycete order, and living upon 

 sugary material or on fruits of the most various kinds. 

 They consist of single cells and multiply by a peculiar 

 process of budding. A small projection appears at one 

 end of the cell, enlarges, and eventually breaks off 

 when it is mature. Sometimes these cells cling 

 together in chains or colonies, which may consist of 

 30-40 cells. The cells vary in shape, but are generally 

 round to ovoid, or sometimes oblong or cylindrical. 



When yeast is placed in a sugar solution, it absorbs 

 the sugar. The protoplasm then secretes a certain 

 ferment, which breaks up the sugar and alcohol is 

 produced, which is excreted through the wall into the 

 liquid.^ This ferment, or enzyme, is probably a nucleo- 



^ There is some doubt as to this being the correct view, 



