Robbins • The Importance of Plants 



coal, cork, and other plant tissues. Tlie 

 discovery of the nucleus is generally 

 ascribed to Robert Brown, botanist, 

 who made his announcement in 1831. 

 The first careful description of cell 

 division we owe to the botanist Hugo 

 von Mohl, who introduced the term 

 "protoplasm" in its present sense. 

 Chromosomes were figured by the 

 botanist Anton Schneider in 1873 and 

 first adequately described by Stras- 

 burger in 1875. 



In manv other directions we find 

 that research with plants has led to 

 fundamental discoveries. The investi- 

 gations of Payen and Persoz in 1833 

 on the diastatic activity of germinated 

 barlev opened the door to the field of 

 enzvmes. Mendel's laws, the founda- 

 tion of our understanding of heredity 

 and genetics, were discovered by experi- 

 menting with peas. The idea of hor- 

 mones was first presented by the 

 botanist Sachs in 1880. The essential 

 nature of the so-called minor essential 

 mineral elements, for example, manga- 

 nese, copper, and zinc, was demon- 

 strated by Bertrand and his coworkers 

 for the black mold Aspergillus niger 

 considerably before their importance in 

 animal nutrition was recognized. The 

 discovery of the nature of virus dis- 

 eases to which belong the agents re- 

 sponsible for smallpox, yellow fever, in- 

 fluenza, poliomA elitis, virus pneumonia, 

 foot and mouth disease, hog cholera, 

 rabies and many other afflictions of 

 man, animals, and plants began with 

 experiments by Iwanowski in 1892 on 

 the mosaic disease of tobacco and was 

 completed by Stanley in 1935 by the 

 isolation from tobacco afflicted with 

 mosaic of the active agent as a nucleo- 

 protein of high molecular weight. The 

 influence of day length on reproduction 

 was demonstrated for plants by Garner 

 and Allard some years before the cor- 

 relation of reproductive activity in 

 animals and day length was investi- 

 gated. 



5 



Perhaps nowhere is the importance 

 of work with plants for scientific ob- 

 jectives of general application demon- 

 strated better than that which has been 

 carried on with yeast. Pasteur's investi- 

 gations on fermentation contributed in 

 a major way to the germ theor\' of dis- 

 ease and to his later discoveries in the 

 field of medicine. Investigations on the 

 chemical changes induced in carbohy- 

 drates by yeast have had an immense in- 

 fluence on our knowledge of respiration 

 and the intermediar)^ metabolism of 

 carbohydrates in animals, including 

 man. At least two vitamins, panto- 

 thenic acid and biotin, were discovered 

 from a study of yeast. 



Many other examples could be cited 

 illustrating the importance of research 

 on plant material. Wliat I have said, 

 however, will suffice to show that the 

 study of plants has given us in the past, 

 as it will in the future, concepts of gen- 

 eral significance in biology, a knowl- 

 edge of principles applicable to other 

 living things, including ourselves. 



RECREATIONAL VALUE OF PLANTS 



I scarcely need call your attention 

 to the recreational value of plants. The 

 opportunity to enjov flowers, shrubs, 

 and trees acts as an antidote for the 

 artificiality and tension of city life re- 

 lieves the drabness and monotony so 

 frequently associated with existence in 

 a small town or in the country, and 

 satisfies a deep-seated desire in all of us. 

 It cannot be expressed in units of value, 

 though it has been recognized in art, 

 poetw, architecture, and design since 

 the beginnings of recorded histon-. 



Someone has said that gardening 

 and a love of gardens are essential com- 

 ponents of a full, sane, and rounded 

 life, and traffic with the soil and the 

 green things that grow from it is one of 

 the noblest and most healthful associa- 

 tions man may adopt. To own a bit of 

 ground, dig it with a spade, plant seeds 



