Theories Concerning Photosynthesis

  • The many theories which have been advanced concerning the nature of the chemical changes which are involved in photosynthesis have served as the basis for much experimental study of the problem. The following brief summary will serve to point out the general trend of these investigations and the present state of knowledge concerning the chemistry of photosynthesis.

    Von Baeyer, in 1870, advanced the hypothesis that the first step in the process is the breaking down of carbon dioxide into carbon monoxide and oxygen and of water into hydrogen and oxygen; that the carbon monoxide and hydrogen then unite to produce formaldehyde, which is immediately polymerized to form a hexose.

  • Flowers, then, have things to offer to insects which the latter need. Nectar and pollen are the chief, and where these merely bread and butter objects are not enough, or sometimes in addition to them, the flower is dressed out in gorgeous colors or perfumed with a fragrance beyond the dreams of the fairest bride. What insects do to complete the fertilization of such a legion of beauties makes up the romance of the flowers. Perhaps not even in man himself is this creation of new life so surrounded with beautiful ideas. Also, as in man, it sometimes is bound up with an almost fiendish cruelty and cunning. Some of these visitors and what they do, but unfortunately only a very few, can be mentioned here.