SPECIAL ASPECTS OF NUTRITION OF PLANTS 133 



diastase). A well-known animal diastase (ptyalin) is present in 

 the saliva of the mouth, which is necessary as one step in the 

 digestion of starch by animals, thus the importance of thorough 

 mastication of the food to mix the saliva with it. Leaf diastase 

 is formed in the leaves of green plants to change the starch 

 formed during the day into sugar so that it can be transported to 

 other parts of the plant. M alt diastase is formed in seeds and 

 is especially abundant in barley which is used to make "malt" in 

 the breweries. The diastase dissolves the starch to sugar, and 

 then enzymes of the yeast ferment the sugar to alcohol. Taka 

 diastase is a special diastase formed by a mold fungus (Asper- 

 gillus oryzce) which grows on rice grains. The fungus excretes 

 the diastase, which acts on the starch in the rice, converting it 

 into sugar. Taka diastase is very powerful and abundant. It 

 is extracted from the fungus and sold for medicinal purposes. 

 It is used by people who have weak digestion to aid in the di- 

 gestion of starchy foods. Many of the plant diastases are very 

 powerful; a small quantity can dissolve a great deal of starch 

 without in the least diminishing its activity. Oil products in 

 seeds, etc., are rendered available for plant food by a ferment 

 called lipase, cellulose (in some seeds) by a ferment called cytase, 

 protein bodies by ferments called proteases, and albuminoids 

 by a tryptic ferment. 



