This is a true picture of one class of cell products, the enzymes; and it represents with considerable accuracy two other products of the cell, the vitamines and the hormones. These three wonderful agencies challenge our interest and provoke a tremendous amount of research at present because they are so far-reaching in their effects and because they hugely baffle any attempt to isolate or identify them.
©1931 by Iowa State Teachers College
Getchell, R. W.
Science Bulletin: Vol. 3:
8, Article 3.
Available at: https://scholarworks.uni.edu/science_bulletin/vol3/iss8/3