The different physical requirements of the plant supply also the explanation of the fact that different plants, grown in the same soil, supplied with the same food, yet vary so greatly in chemical composition. Thus, when wheat and clover are grown together, and afterwards analyzed, it is found that while lime is abundant in the clover, it is relatively in small quantity in the wheat; and silica, which is abundant in the wheat, is absent from the clover. Poisonous substances even may be absorbed, if they are of such a nature as to be capable of absorption; and so the plant may be killed by its own action—by suicide, as it were.
The entrance of water into the plant and the entrance of those soluble materials which a plant derives from the soil are therefore illustrations of the process of osmosis, and are subjected to all the conditions under which osmosis becomes possible, or under which it ceases to act.
One thing we must strive to impress forcibly on the reader, because, if the notion is well grasped, it will enable him to understand plant life so much more vividly. We allude to the continual changes that are going on throughout the whole living fabric of the plant while in its active condition. Cell membrane, the protoplasm, the entire mass of liquid and solid constituents of which the plant consists, are, as we have seen, made up of molecules, each, as it were, with a life of its own, undergoing continual changes according to different circumstances, acting and reacting one upon another so long as any active life remains.
By REV. J. H. VINCENT, D.D., SUPERINTENDENT OF INSTRUCTION C. L. S. C.
Readings for the month: “Easy Lessons in Vegetable Biology,” by Dr. J. H. Wythe; “Canadian History;” Chautauqua Text-Book No. 24; “Biographical Stories,” by Nathaniel Hawthorne; Required Readings, in THE CHAUTAUQUAN.
Memorial Day, Sunday, December 9, “Milton’s Day.” See “Memorial Days,” Chautauqua Text-Book, No. 7. Monday, December 10, may be used if preferred.
Remember the 5 p. m. Sunday “Chautauqua Vesper Service.” Observe the hour personally or as local circles. Now and then a brief public service at this hour may be very profitable.
There can be no substitute accepted for the “Preparatory Latin course in English.”