226 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1952 



Plant life is essential to human existence, and the chemist will con- 

 tribute much in this field. By well-known processes of selection and 

 plant breeding, the agriculturist has succeeded, during the 40 years 

 that soybeans have been grown in this country, in increasing the oil 

 content from 16 or 17 percent to 21 or 22 percent. Hybrid seed corn, 

 which is now widely used by farmers, results in an increase in crop 

 yield sometimes as high as 50 percent, essentially without any addi- 

 tional requirements in the soil. The inference from these achieve- 

 ments is that proper chemical treatment of plants could result in 

 fundamental modification of their metabolism. By standard agri- 

 cultural development methods the future will see food crops in which 

 the size of the plant is dwarfed and the fruit, kernels, or ears of corn 

 are of greater size. In this way, more plants can be grown in a given 

 area and the subsequent crop will be larger. 



Another means of providing a greater crop from a given acreage is 

 by plant-growth stimulants — chemicals that accelerate the growth and 

 maturation of plants. Several are known, and chemists will discover 

 new and better ones, with the eventual result that two crops of the 

 same or different plants may be grown during the normal season where 

 now only one crop is possible. Perhaps during these experiments we 

 may find substances that will not merely speed up the growth of a 

 plant but cause its fruit to be larger — for example, pears, apples, or 

 oranges the size of grapefruit. If this seems fantastic, just consider 

 the coconut-milk factor recently discovered in academic experiments. 

 On its addition to a basal nutrient agar medium, mature plant cells 

 are caused to subdivide ; for example, cylindrical slices of carrot will 

 grow rapidly. 



Plant physiology is still in its infancy, and it must be better under- 

 stood before rapid advancement in the cultivation and control of 

 plants can reach a maximum. Experiments performed in Germany 

 during the past 10 years permit one to envisage remarkable achieve- 

 ments in the future. In the flowers of the forsythia, those early 

 yellow blooms which decorate gardens in many parts of the country 

 in the early spring, it has been observed that the pollen of one flower 

 never fertilizes the stigma of the same flower, nor does it fertilize a 

 flower of the same type whether the flower is on the same or another 

 bush. Formation of seed occurs in flowers where the pollen comes 

 from long stamens and is accepted by flowers with long stigmas. 

 Similarly, pollen from flowers with short stamens fertilizes flowers 

 with short stigmas. Other combinations result in nonfertilization. 

 A chemical study of pollen from long and short stamens has revealed 

 that, although closely related chemicals are in each, they are actually 

 different. With this discovery, a procedure was developed whereby 

 fertilization of these flowers could be made to occur by chemical treat- 

 ment where it would not have occurred naturally. 



