America from which quinine is made is the most important recent development. These trees were taken to India in 1861 and have been successful. It is another illustration of the fact that man cannot longer depend on wild plants but must select and grow the types needed by him, for the world must draw its supplies from the areas in which given plants prosper. Man has long cultivated many of the plants from which he has made his stimulants. To the tea and opium of Asia must be added the coffee and cola of Africa, the coca of South America and the tobacco of tropical America. No good habit has spread over the world faster than the use of tobacco. Our southern states produce to-day about onethird of the world's supply. Ornamentals As these lines are being written a glance out of the window reminds one that "man does not live by bread alone." The grackles are building their nests in the Norway spruces. The Hugonis rose of Asia is putting on a coat of green; bleeding hearts and peonies are pushing through the ground; the crocus is in bloom. From time immemorial man has sung of the beauty of the flowers and long ago began their cultivation. As civilization developed and commerce grew the world has been ransacked to find flowers, shrubs and trees to be used as ornamentals. Gradually man changed from the collecting of wild plants to the growing of selected types and the nurseryman appeared, drawing his supplies from all over the earth. As population increased it became necessary to grow flowers in quantity. From the greenhouses almost in sight of the writer thousands of sweet peas, roses and carnations are being cut for the market. A little later there will be fields of peonies whose cultivation was first undertaken in China, and of gladioli which came to us from South Africa. Many of our shade trees, even, have been drawn from other lands as the eucalyptus of the Pacific coast witnesses. In return we have supplied laurel and rhododendron to Europe and have sent the agaves and opuntias to the warmer lands. The last have escaped from cultivation in the semiarid countries and have become a veritable menace to the farmers of parts of Australia. We have been so anxious to collect strange forms from other countries that we have often neglected the best of our own species. The dogwood is one of the finest flowering trees of the world but there are few to be found in the yards of our eastern farmers. Ornamentals offer an interesting sidelight on history. Commerce demands that necessities such as foodstuffs shall be standardized and new things must be tested and introduced gradually. The desire to get something "different" stimulates variety in ornamentals. In a catalogue on my desk of a leading supply house all the seeds for farm and garden are described on fifty pages but flower seeds and plants cover one hundred pages. SIGNIFICANCE OF DOMESTICATION Earlier man first cultivated annuals or biennials rather than the more slowly growing perennials. The last he used in countless ways but depended on the wild supply. Only recently has man begun to cultivate trees to any great extent, but this has become an immediate necessity and the industry is spreading rapidly. The story of the domestication of plants and animals is but one aspect of the upset of the balance of nature which has been discussed. Does the average person realize that man is creating a new world? Does he visualize the fact that the larger mammals are disappearing from earth, save those which man keeps as domesticated helpers, to such an extent that scientists are already speaking of the end of the era of mammals? Does he realize that even the trees of earth are doomed save those which man preserves? No longer can man depend on wild plants and animals to supply his needs. He is replacing them with newer sorts. Can these newer types survive without man's protection? It is evident that the chief problem of man in the future is to lie in the effort to control the smaller forms of life, for it should not be forgotten that if we compare the smallest with the largest forms of animals the average will be about as big as a good-sized fly. POSSIBLE UTILIZATION OF BACTERIA Until very recently man's use of the lower forms was largely accidental and unconscious. Long ago, to be sure, man learned the difference between leavened and unleavened bread but the cause of the difference was not understood. Long ago he learned to transfer some of the "mother" from an old lot of vinegar to a new barrel but it was not until Pasteur and his contemporaries of the middle of the last century discovered the nature of fermentation as well as of contagious diseases that the era of the conscious use of yeasts and bacteria became possible. In most cases, even to-day, man but provides favorable conditions for the growth of bacteria and trusts that the helpful forms will do the work desired. This is the case in the purification of sewage in tanks and the fermentation of ensilage in silos, and in the ripening of hay in mow or stack. It is the case also in the retting of flax, the tanning of leather, the making of pickles and in homemade cream and butter. In the creameries and cheese factories as well as in the wineries greater care is now given to the exclusion of harmful types. Yeast has become a standardized product. In the fight against disease we find the most discriminating use of bacteria to-day with the greatest care in the production of pure strains. There seems to be a definite field for their use in industry in the near future, as in chemistry, for some of the bacteria can distinguish between different sugars far more accurately than any man. All this is but an indication that man will learn to utilize (domesticate does not seem to be the proper word) many of the microscopic forms of life whose very existence was unknown to him a few years ago. A century hence a family will probably send over to the neighbors for a batch of microbes as nonchalantly as it now asks for the loan of a loaf of bread. REFERENCES 1. After FINCH and BAKER, Geography of the World's Agriculture. 2. A. ANTONIUS, Stammesgeschichte der Haustiere, pp. 241ff. 3. C. KELLER, Derivations of European Domestic Animals, pp. 483ff. 4. Ibid., p. 490. 5. A. DE CANDOLLE, Origin of Cultivated Plants, p. 451. 6. Ibid., p. 448. CHAPTER VII MAN AND HIS MACHINES Man's earliest arms were fingers, teeth and nails, -LUCRETIUS THE DEVELOPMENT OF CULTURE Historically speaking the most important discoveries and inventions of man are not those of recent years, the electric light and radio, for example, but those which for long ages and over wide expanse of earth have been used by man in his daily life. Who invented the bow and arrow, perhaps the most useful tools in the securing of game and the best of weapons, until the invention of the gun? What genius discovered the art of fire-making and made possible the use of cooked food? Was it a woman or a man who first used needle and thread? We cannot hope to answer such questions. The best we can do is to keep digging away until the story of the development of man's culture is better known than it is to-day. It so happens that the history of Europe is better known than that of any other part of the world. This is true even if we are not certain of the race to which the leaders of the classical culture of ancient Greece belonged. Here we have the best evidence of the culture of primitive man. Our classification, therefore, must be based on Europe in spite of our knowledge that the culture centers of Asia are much older. Save for the region east of the Mediterranean, Asia is almost |