124 TEXT-BOOK OF FUNGI 



Intramolecular respiration, or the liberation of carbonic 

 acid in an atmosphere deprived of oxygen, takes place in 

 some fungi, according to Diakanow; but only when the 

 nutrient medium contains a fermentable substance. 



Bonnier and Magnin, Ann. Set. Nat., ser. 6, 7, p. 210 

 (1884). 



Diakanow, Archiv. Slav, de Biologic, 1886, p. 531 ; 1887, 

 pp. 6, 31, and 121. 



Kolkwitz, Pringsh. Jahrb., 33, p. 128 (1899). 



FIXATION OF FREE NITROGEN BY FUNGI 



Ternetz has announced the discovery of a fungus in 

 peaty soil which fixes the free nitrogen of the air. The 

 mycelium is septate and branched. Pycnidia containing 

 hyaline conidia are formed ; these conidia are so very 

 minute that they pass through thick filter-paper. 



Ternetz, Ber. d. deutsch. Bot. Ges., 22, 267 (1904). 



ENZYMES AND FERMENTS 



Enzymes are substances elaborated by living cells, and 

 possess the property of effecting chemical changes in 

 certain substances even after their removal from such cells ; 

 hence the action of an enzynie is purely chemical, as 

 opposed to vital. If an enzyme is precipitated by alcohol, 

 and afterwards properly prepared, the resulting precipitate, 

 dissolved in water, produces exactly similar changes in a 

 given substance to those effected by an extract obtained 

 from living cells. Enzymes act by causing the molecules 



