GERMINATION AND SPRING GROWTH 69 



the common use of which is the clotting of milk. Pectase 

 is an enzym found in plants, which has the property of 

 causing the pectic substances which cement the cells 

 together to coagulate and form a firm jelly-like substance. 

 It acts in conjunction with the salts of calcium. 



The fermentation enzyms, employed in raising bread 

 dough, in making wine, beer, and cheese, etc., effect 

 chemical changes in complex non-nitrogenous organic 

 compounds resulting in the production of gas, alcohol, or 

 other desired substances. It is probable that fermenta- 

 tion enzyms are concerned in disease due to bacteria or 

 fungi parasitic in human beings. 



Germination and Spring Growth. — The action of 

 enzyms is illustrated in remarkable degree in the germina- 

 tion of seeds and in the resumption of growth which has 

 been interrupted by cold or drought. The sprouting and 

 growing embryo and the developing seedling are nour- 

 ished by the food stored in the seed, which is digested 

 and made available by the enzyms which work on starch, 

 cellulose, fats and oils, and the proteins. Meantime, 

 other enzyms, the oxidases, are active in bringing about 

 the oxidations which supply the young and growing plant 

 with necessary energy. Similarly, spring growth, con- 

 sisting in the production of new foliage, in elongation 

 and thickening, perhaps in blooming and fruiting as well, 

 is made possible by the digestion and use, by means of 

 enzyms, of food stored in insoluble form in parts of the 

 plant often remote from the seat of growth. Enzym 

 action therefore underlies the production, storage, move- 

 ment, and use of food in plants and animals. Enzyms 

 are produced by, and are always present in, the living 

 protoplasm, which uses them in effecting and regulating 

 chemical change. 



