While there is a great variety of enzymes which may be produced by a single individual organism, the same enzyme may be found in the greatest variety of organisms; as, for example, the protease trypsin, which has been found in several species of bacteria, in the carnivorous plant known as "Venus' Fly Trap," and in the human pancreas, as well as that of all other animals. FURTHER STUDIES NEEDED From the discussions which have been presented in this chapter, it is apparent that the enzymes play a tremendously important part in vital phenomena, by controlling the rate at which the biochemical reactions take place in the cells of the living organism. The means by which the protoplasm elaborates these all-important chemical compounds are as yet absolutely unknown. Even the nature of the enzymes themselves is still a matter of speculation and study. Much intensive study is needed and should be given to these matters, for the purpose of elucidating the methods by which the enzymes accomplish their remarkable catalytic effects, and, if possible, the actual chemical nature of the enzymes themselves. It is conceivable, of course, that if the latter object of these studies should ever be reached, it might be possible to synthetize enzymes artificially, and so to develop a means for the artificial duplication of the synthesis of organic compounds with the same velocity that this is done in the plant cells. Such a result would have a scientific interest fully as great as did Wöhler's artificial synthesis of urea, which proved that there is no essential difference in character between the compounds which are the products of living organisms and those which are produced in the laboratory; and, at the same time, might have an immensely more important practical bearing, since it would lead the way to the artificial production of the carbohydrates, proteins, fats, etc., for which we are now dependent upon plant growth as the source of these materials for use as human food. References BAYLISS, W. M.--"The Nature of Enzyme Action," 186 pages, _Monographs_ on Biochemistry, London, 1919 (4th ed.). EULER, H., trans. by POPE, T. H.--"General Chemistry of the Enzymes," 319 pages, 7 figs., New York, 1912. EFFRONT, J., trans. by PRESCOTT, S. C.--"Enzymes and their Application,--Enzymes of the Carbohydrates," 335 pages, New York, 1902. EFFRONT, J., trans. by PRESCOTT, S. C.--"Biochemical Catalysts in Life and Industry--Proteolytic Enzymes," 763 pages, New York, 1917. GREEN, J. R.--"The Soluble Ferments and Fermentation," 512 pages, Cambridge, 1901, (2d ed.). GRUS, J.--"Biologie und Kapillaranalyse der Enzyme," 227 pages, 58 figs., 3 plates, Berlin, 1912. HARDEN, A.--"Alcoholic Fermentation," 156 pages, 8 figs., Monographs on Biochemistry, London, 1914. PLIMMER, R. H. A.--"The Chemical Changes and Products Resulting from Fermentations," 184 pages, London, 1903.