Robbins • The Importance of Plants 



unused. The wide contacts brought 

 through this war to hundreds of thou- 

 sands of our young men, many of them 

 already trained in science, may result in 

 new and important uses for plants. The 

 opportunity exists because not only are 

 familiar plants incompletely inyesti- 

 gatcd, but there are considerable areas 

 of the earth botanically unexplored and 

 thousands of species of plants still un- 

 known to science. Any one of them 

 might become as important to us as 

 Penicillium notatum. 



I cannot close this discussion of the 

 economic aspects of plants without 

 referring to their importance in disease 

 and decay. It is not my intention, how- 

 ever, to discuss bacteria, yeasts, and 

 molds as causes of disease in other 

 plants and in animals and man, nor to 

 elaborate on their relation to decay ex- 

 cept to call attention to the importance 

 of the fungi in rotting wood and cloth, 

 molding food, short-circuiting electrical 

 instruments, and deteriorating optical 

 equipment in the Tropics. Although 

 those of us who liye in the Temperate 

 Zone are acquainted with the fungus 

 rots of telephone poles, railroad ties, 

 and house timbers and the minor losses 

 from mildewed curtains or moldy food, 

 we haye little conception of the de- 

 structiyeness of molds in the moist 

 Tropics. Their control is a matter of 

 major concern. 



Another way in which plants con- 

 tribute to our economic system is 

 through the association of microorgan- 

 isms in the formation of various prod- 

 ucts, for example, cheese which de- 

 pends upon the activity of the lactic 

 acid and other bacteria and various 



molds; beer, wine, and other fermented 

 liquids produced by \east; sauerkraut, 

 vinegar, soy sauce, and many others less 

 well known or desirable. Bacteria, 

 3'easts, and molds as we learn to know 

 them better are increasingly used for 

 producing specific chemical compounds 

 which are beyond the skill of the labo- 

 ratory worker or which can be made 

 more cheaply bv the microorganism. 

 Alcohol, acetic acid, acetone, glycerine, 

 citric acid, gluconic acid, and riboflavin 

 are some of these compounds. Tlie 

 most famous and illustrious addition to 

 this list is, of course, penicillin. 



"Botany," said Thomas Jefferson, 

 "I rank with the most valuable sciences 

 whether we consider its subjects as fur- 

 nishing the principal substances of life 

 to man and beast, delicious varieties for 

 our tables, refreshments from our or- 

 chards, the adornment of our flower- 

 borders, shade and perfume of our 

 groves, materials for our buildings or 

 medicaments for our bodies." 



Jefferson wrote these words in 1814. 

 Priestley had but recently demonstrated 

 that plants produce oxj'gen; the unique- 

 ness and importance of photosynthesis 

 was still to be recognized; coal and pe- 

 troleum were still to be developed; 

 vitamins and amino acids, the relation 

 of plants to them and their importance 

 in animal nutrition were unknown; 

 rubber was a plaything; the relation of 

 bacteria and molds to disease and decay 

 was still to be discovered and penicillin 

 was a long way in the future. Thomas 

 Jefferson estimated the importance of 

 plants on the basis of the knowledge 

 about them available in 1814. What 

 would he have said today? 



QUESTIONS 



Justify the statement: "Plants are the 

 basis upon which all other life de- 

 pends." 



Define or explain the process of 

 photosynthesis. 



What is the relationship of coal and 

 oil to photosynthesis? 



What are said to be the three most 

 important subjects for scientific re- 

 search? 



