Some Newly Discovered Plant Principles.


In Agriculture we work with plants. We place them in the

ground and see them develop from the seed to maturity. We cultivate


them and feed them fertilizers. The product may be good or it may


be bad. The plant j either worked well or it has not; but we can


not tell exactly why it has or has not worked well. The reason lies

how
in the fact that we know very little about the plant actually works.


In the living plant we deal wi th a mechanism which we c an

not examine in its most vital parts; because, the morzent we in any way


interfere with the living Protoplasm, we kill it; and the dead propoA-


lasm is a wholly different substance fror' the living Protoplasm.


Altho we cannot analyze the living Rxagm6rotoplasm, we


can study the products of its~ action, -,nd its action upon the non-


living matter whict'is presented it Ps food. In the process of fermen-


tation we have an example of both the product of its action, and its


action upon non-living matter. Fermentations are familiar to every


one. The cane syrup ferments if not properly taken care of; the


yeast ferments, making possible the l1rge plump loaves of bread; the


milk ferments, which is another way of saying that it sours.





In all these cases the fermentation is brought about by

the action of living protoplasm. Contaminations such as yeasts, bac-


teria and moulds, which are all living plants, have fallen from the

air into the syrup. There they have grown and multiplied, for they


have found a favorable place tp live, The syrup furnishes them a


super- abundance or food. Their living protoplasm breaks down the syrup


into alcohol and carbon dioxide, which is a gas commonly known as


carbonic acid gas. The gas collects and rises in the syrup giving it


its frothy appearance; and the alcohol present gives it its character-


istic odor,


In the milk, myriads of small bacteria have found a favor-


able place in w.ich to live. They are growing and multiplying, break-


ing down the milk sugar into Lactic acid which gives the milk its


sour taste.


In each of these cases we suppose that the protoplasm was


in direct contact with the syrup and with the milk, and provoked the


decomposition of each.


In the case of the yeast, which is a small one called plant,


we have a decomposition of sugar into the alcohol and carbon dioxide.


But the decomposition is not brought about by the direct contact of


the protoplasm with the sugar. Instead the protoplasm has secreted







a substance which we will callka plant Principle, and which is known


in scientific literature as an enzyme, that stimulates the sugar to


break down th6o alcohol and carbon dioxide.


Altho we have known for several centuries that the yeast


plant can provoke the braking down of sugar, it has only recently


been discovered that the yea_ t does so by its protoplasm secreting a


plant principle or enymne that does the work. This substance has


been named Zymase.


These plant principles are very abundant in the vegetable


kingdom. Thebacteria in the soil secrete them, thus locking u.p the


nitrogen from the air into ammonia and related compounds. One mould


fungus is known to secrete ten different ones. They may be equally


abundant in some of the higher plants. Seeds germinate by their con-


verting the stored food into a form usable by the young plant until


it can become established in the :oil. The fertilizers taken f om the


soil are modified greatly by the enzymes in the plant before they are


in a condition to be used by the protoplasm. The enzymes change the


plant food into an insoluble form that it may be stored; and later


changes it back into the soluble form that it may be carried to all


parts of the plant for use. They are very active during the growth


and ripening of the fruit.






They aid in the carrying on of all the life processes, such


as digestion, respiration and growth. During respiration, the union


of the oxygen with the tissue is accomplished by their help. Digestion


is almost wholly an enzyme action.


On the other hand, instead of being friends, they maybe an


aid to the enemy of the plant; or they may even be the enemy itself.


The fungus bores its way into the plant by means of the enzymes it


secretes. The Mosiace Dise of the Tobacco is thought to be due to an


enzyme.