Chap. 4 PLANTS PROVIDE FOR THEMSELVES AND THE ANIMALS 



r 



55 



Fig. 4.4. Carolus Linnaeus (1707-78), the Swedish botanist, at age 25, in Lap- 

 land dress, holding his favorite, the twin-flower (Linnaea) and equipped with a col- 

 lecting kit for his Lapland journey. Linnaeus made one of the great contributions 

 to natural sciences, the two-word naming (binomial nomenclature) of plants in 

 1753 and of animals in 1758. His work made way for the natural arrangements of 

 living organisms. (Courtesy, Greene: Carolus Linnaeus. Philadelphia, Christopher 

 Sower Co., 1912.) 



store it as chemical energy in carbohydrates (starches, sugars). The process 

 of photosynthesis or carbohydrate-making is the greatest chemical industry in 

 the world with the widest importance of all biochemical reactions. It is carried 

 on by all chlorophyll-bearing plants from microscopic algae to the largest 

 trees. Red and brown seaweeds and plants of various other colors contain 

 chlorophyll cloaked with pigments. Although the manufacture of food by land 

 plants is enormous, it is estimated that 90 per cent of the total is produced by 

 the large (seaweeds) and small algae of the ocean (Fig. 4.5). They constitute 

 the basic food supply of the great animal populations of the seas. In general, 

 the plants themselves use a good deal of the food which they produce. Much 

 of it is decomposed into water, carbon dioxide, and mineral salts by the decay 

 of leaves and plant bodies in water and on land, and is used over again by 

 the plants. 



Materials and Conditions. The natural conditions for photosynthesis include 

 the presence of chlorophyll, the energy of sunlight or artificial light, water, and 



