January 7, 1921] 



SCIENCE 



equipment and money and should do good 

 ^lOrk. 



I POLLINATION OF FLOWERS 



Another phase of the subject of economic 

 botany is that of pollination. Progress was 

 slow. Geoffroy, who as early as 1711 made 

 some observations on the nature of the style, 

 is said to have conducted some experiments 

 with maize; however that may be he did make 

 use of the work of Camerarius. Geoffroy con- 

 cluded from various sources that fertilization 

 was a kind of fermentation, but he was in- 

 clined to accept a second view of Morland that 

 the pollen grains contain the embryo which 

 find their way to the seed. We may also recall 

 the work of John Logan, at one time gov- 

 ernor of the colony of Pennsylvania, who 

 conducted experiments on the fertilization of 

 maize, in which he noted that cobs covered 

 with muslin did not produce seed, but seed 

 was formed on cobs where pollen came in con- 

 tact with the stigmas. Logan suggested that 

 the wind carried the pollen. Gleditsch in a 

 study of one of the palms {Chammrops 

 fiutnulis) strewed loose dried pollen on the 

 stigmas of a female plant which produced seed 

 iWhich later was planted and germinated; a 

 simple experiment but a convincing one to the 

 botanists of the time, who had never seen pol- 

 lination demonstrated before. Philip Miller 

 in 1751 calls attention for the first time to the 

 importance of insects in the pollination of 

 tulips. The first scientific experiments on hy- 

 brids were made by Koelreuter, who discovered 

 the use of nectar and the importance of in- 

 sects in the pollination of flowers. Koelreuter 

 clearly set forth the facts that the mingling 

 of two substances produced a seed. These 

 general statements as set forth by him still 

 hold true. He was a skillful experimenter in 

 the hybridizing of plants. The work of 

 Sprengel on the pollination of flowers is well 

 known to the older botanists. His sharp dis- 

 criminating observations on the relation of 

 insects to flowers were little understood at the 

 time. The full import of these problems were 

 recognized by Charles Darwin, who in his 

 masterly way showed the application of this 



in practical problems. Earlier Sir Andrew 

 Knight had demonstrated " that no plant fer- 

 tilizes itself through an unlimited number of 

 generations." Dr. Gray put this in a much 

 more terse way. A score of investigators like 

 Hermann Mueller, Fritz Mueller, Delpino, 

 Ludwig Asell, Hilderbrandt and in our coim^- 

 try men like Gray, Trelease, Eiley, Foerste, 

 Beal and Robertson demonstrated the use of 

 insects in pollination and the application of 

 this fact to important agricultural crops. These 

 fundamental facts are fully recognized to-day 

 in the growing of apples, alfalfa, sweet clover, 

 melons, squash and cucumbers. The orchard- 

 ist recognizes the importance of bees in con- 

 nection with the growing of apples, pears and 

 plums. The farmer recognizes the importance 

 of bees in the alfalfa and sweet clover fields, 

 just as Charles Darwin recognizes that the 

 bumble bee is important in the red clover pol- 

 lination. In this connection, as an economic 

 problem, I may call attention to the honey 

 flow in flowers. It is true beekeeping is only 

 one of our minor agricultural problems de- 

 pendent entirely on the relative abundance of 

 honey plants in a given region. There are a 

 great many interesting physiological problems 

 in connection with nectar secretion, as Kenoyer 

 has shown. One wonders why alsike clover 

 scarcely yields any nectar for bees in Iowa 

 and yet in some regions of the country it is 

 one of the best of nectar plants. There is 

 seldom any nectar in buckwheat flowers after 

 10:00 A.M. in Iowa, and yet in sections of the 

 United States the period of nectar flow is 

 much longer. Is soil alone a factor or is 

 moisture an important factor, or are the two 

 factors combined? We have enormous ex- 

 panses of waste land along our highways in 

 the United States, why not combine the es- 

 thetic with the economic if we can find plants 

 that are suited for such places that will yield 

 good returns for the beekeeper. 



PLANT BREEDING 



I heard a practical fruit grower in Iowa say 

 the other day when a new chance seedling 

 apple was shown me that nearly all of the new 

 good things in the fruit line are chances; that 



