Gift Of Green (1946)

[Music] thank you it's a green world we live in and lucky we are that it is yet how few of us realize the significance of the plants which make it green in this color of nature symbol of Youth and growth the green plants from lowly grass to lofty trees hold the key to life on Earth the beauty of this green world we take for granted the pine trees of Northern woods the wind-shaped cypresses the giant forests of snow-clad Western slopes the bright Lush growth of warmer places public lands in kind and number endless trees to give Beauty trees to bear fruit trees to shelter and shape how much we owe to the trees to all green plants large and small green plants green leaves such as these through a Wonder working substance they contain trap and store the energy of the Sun for man's use without the green plants we could not live by a process peculiar to themselves they build within themselves something vital to all existence for this process two building materials are needed one is water the water particle or molecule contains two atoms of hydrogen and one of oxygen the other building material is air not all parts of the air but only colorless invisible carbon dioxide of which the air contains hardly more than a Trace we are all familiar with carbon dioxide it is the gas returned to the air When Animals breathe and when fuels burn the carbon dioxide molecule contains one atom of carbon and two of oxygen oxygen has a free element makes it possible for us to breathe we cannot see oxygen in the air but if we expose a water plant to sunlight oxygen given off by the plant Rises to the surface in bubbles oxygen however is not one of the plants building materials but a byproduct of its work if we cut off the sunlight the bubbles slow down and stop without the sun this activity ends [Music] like rootlets plant is pulled from the ground but when seeds are germinated in a covered dish these delicate white hairs are easily visible these root hairs hear greatly magnified are important to the life of plants through them water is drawn from the soil and into the root through the root and up the stem the water passes into the veins of the green leaf a greatly enlarged view of the Leaf's Underside reveals part of its intricate structure here among the epidermal cells are minute openings or pores called stomata there are thousands of these stomata in one square inch of leaf surface now let's look inside the leaf exposed to direct sunlight is the upper skin or epidermis under this transparent surface is a layer of cells like Palisades in this palisade layer is concentrated most of the Leaf's green coloring matter the small green bodies here faintly seen are called chloroplasts under the palisade layer is a spongy storage layer just above the lower epidermis here we see in cross-section a stoma or pore through thousands of such pores air with its particles of carbon dioxide gas enters the plant and makes its way into every living cell through these same pores part of the water drawn from the soil escapes into the air enough water is retained however to permeate every cell of the leaf the carbon day on the water finally reached the living chloroplasts here they are many many molecules of carbon dioxide and of water inside a chloroplast here too is the key to an everyday wonder it is called chlorophyll and chlorophyll is what makes plants green chlorophyll has the power to trap the sunlight and harness its life-giving energy sunlight air water and chlorophyll with these the plant's work is performed the process is called photosynthesis meaning putting together or building with the aid of light more oxygen is produced by the process than is used by the plant this oxygen is returned to the air and is the oxygen we breathe without which we would die of suffocation and what is built from these simple materials something not at all simple by complex chemical reactions the plant makes a complicated molecule and bound in this molecule is the energy of the Sun this complex molecule formed of simpler molecules joined together represents a food a direct source of energy for living things it takes an infinite number of molecules precisely arranged to make just one Crystal of this food common sugar this Crystal is sucrose though other sugars glucose and fructose were probably made first in the plant what happens to the sugars which the green plants make the sun's energy contained in this food is required first of all for the plant's growth for the formation of new parts [Music] the growth of a fern the opening of flowers processes covering days in nature demonstrate the energy plants derived from the food they make foreign [Music] [Applause] [Music] [Applause] to build its architectural structure like the veins which hold up the broad thin surface of a leaf the Woody trunk of a tree supports the crown of leaves and branches foreign sugar is converted into starch cellulose and lignin many vegetables store converted sugar as starch chemically a close relative of sugar in some plants sugar after undergoing chemical changes is stored as fats or Oils the coconut palm stores in its seed an oil used in foods in soaps and various other products the edible fruit of the Olive Tree is rich in oil [Music] and so is the avocado the plant sugar combines with nitrogen phosphorus and other minerals from the soil to produce the important proteins peas and beans are excellent sources of plant proteins other combinations derived from sugar give man his vitamins not only the well-known leafy vegetables but fruits are important natural sources of vitamins by other Transformations plant sugar goes to form many useful drugs from cincona bark comes quinine among the other drugs which come from plants are digitalis Belladonna and strictly and still other things may happen for the plant is an able chemist the color and fragrance of flowers are made in the plant from sugars [Music] foreign subtropics which takes the place of bread and potatoes in the native diet is rich in sugars the pineapple too has a high sugar content of the 350 000 known kinds of plants man places Chief Reliance on only two the sugar cane and the sugar beet or the sugar he directly consumes sugar cane thrives in the warm humid climate of tropical and subtropical areas its cultivation dates back centuries before the time of Christ and Columbus introduced it to the new world the sugar formed in the leaves is stored in the stalk of the cane [Music] sugar beets are grown in virtually all countries which have a temperate climate in the beat the sugar formed in the leaves is stored in a long white root trains and trucks bring the Beats from field to factory where sugar is extracted from them [Music] foreign the food which the green plants make is their direct source of energy it enables grasses to grow tall as trees like the bamboos in some countries they attain a height of more than 100 feet the strange Saguaro the giant cactus of the Arizona desert in the place of leaves which give off water has developed in its trunk organs to store water having no leaves this adaptable plant makes its food in the tough skin like the Saguaro the smaller cacti grow sharp spines these spines protect them from animals which would eat them for the moisture they store the energy of some plants is sufficient to move rocks and this energy can be destructive to other plants the Strangling fig wrapping itself around the great Live Oak May finally killed the older tree [Music] the wood of these great trees is derived from the sugars made in the leaves this food then is a building material as well as a source of energy it was a building material for the oldest and largest of living things the giant sequoias of California four thousand years old and more and 300 feet high foreign with great skill are the remains of animals which lived in past ages many millions of years ago long before man inhabited the Earth as animals live from Plants today these prehistoric monsters too derive their sustenance from plants then as today even the carnivorous animals eating the Flesh of other animals which lived on plants in the last analysis were dependent on the plants for their food and here embedded in rock are the fossils of plants which lived in those remote ages these prehistoric plants were once green and made their own food the basic food of nature just as the green plants do today but they are more than relics of past ages from such plant remains buried in the Earth for millions of years come the world's sources of industrial power coal is one of these sources of energy coal is a fossil fuel found in the Earth's crust and formed of plants that lived ages ago petroleum is the other source oil in the earth originated from plants and animals and like coals it represents the energy from the Sun stored in sugars made by green plants which grew millions and millions of years ago this stored energy is set free when coal and oil burn man uses it to drive his great Industries [Music] to heat his buildings to light his world at night [Music] foreign by land [Music] see [Music] by air [Music] all of this the power of our complex AIDS we owe to the green plants green plants and what they do with water and air in the sunlight green leaves and the wonder worker in them the sun trap chlorophyll the sun's energy caught and fixed in a gleaming sugar crystal the green plants give to the living world of nature food of man source of his development and Power Through the Ages