66 



samples are ten feet high and others fully low. Some are leafy 

 and others possess almost bare stalks. Some varieties are sturdy 

 and others show a tendency to droop. Every shade of color from 

 a pearly white to a dull black hull is to be seen interspersed into 

 numerous yellow and brown. 



The plant breeder proceeds in this work with as much method 

 and precaution as the breeder of stock. He has, however, this 

 advantage in his favor : the greater number of individual mem- 

 bers to experiment wath and the greatly reduced period of gen- 

 eration. Having decided upon the superior merits of a particu- 

 lar variety, he with infinite care, generally based upon elimina- 

 tion of individuals, selects three of his best plats. The potential 

 yield of each of them is then exactly determined per acre, and 

 the heaviest producer is then reserved as the mother plant from 

 which all future rice of that variety w^ill be grown. In this 

 manner a pure stock of known parentage is determined. 



Each variety in the trial fields is thus treated in successive 

 seasons until the most suitable is determined. This is a long 

 and tedious process. Many beneficial results are also evolved 

 by artificially crossing two or more distinct breeds. This phase 

 of the work is one of unlimited potentialitgies and enables the 

 breeder to attain an ideal standard. If by these methods a rice 

 can be developed yielding one bushel per acre more than is now 

 obtained, the cost of the experiments would be many times re- 

 paid in the first year. But the station confidently hopes to 

 achieve much more than this. 



The methods of improving plants by artificial means may be 

 summarized as follows : 



First : Inducing variation by altering condition of soil and 

 environment, and by conveying the pollen of one variety to the 

 ovary of another. 



Next : The selection of desirable varieties, taking not the 

 seed only, but the whole plant as a unit. 



Lastly : The establishment of the power of the parent plant 

 to transmit its acquired characters to its progeny. 



The artificial crossing of rice, as, of course, with all plants, is 

 brought about by means of the flower, in which the organs of re- 

 production are situated. The rice flower is a perfect one in 

 which both sexes are represented. The six stamens contain the 

 pollen which fertilize the ovary. In the case of the rice flower 

 both cross and self fertilization takes place. When artificial 

 cross fertilization is brought about the plant breeder first re- 

 moves the pollen bearing organs to prevent self fertilization, and 

 also protects the stigma, l^y means of a thin gauze from chance 

 cross fertilization. At the proper time the desired pollen is in- 

 troduced. The resulting cross is a blend of the characteristics 

 of the two parents. Such operations are conducted with as much 

 care as in the breeding of stock, and the results of successful 



