118 Research Bulletin No. 2 
of degree. The breeder who selects for high-oil content from 
open-pollinated plants will, if he persists long enough, succeed 
in producing a type with enough factors for oil production to 
rank as a high-oil type and with these factors sufficiently 
homozygous to insure comparative constancy, while at the same 
time a sufficient number of factors for other minor characters 
are heterozygous to insure a comparatively vigorous strain. But 
by self-pollination, together with the same sort of selection, 
several practically homozygous high-oil strains could almost 
surely have been produced in much less time. And these strains 
would doubtless have been sufficiently unlike in factors for minor 
characters to insure abundant vigor of growth on crossing them. 
While a few years' time may not be an important consideration 
where the character in question can be determined at sight or 
by mere weighing or measuring, in breeding work requiring 
costly chemical analysis it is extremely important that the de- 
sired results be obtained in as few years and therefore with as 
few analyses as possible. 
LITERATURE CITED. 
Belling, John 
Second generation of the cross between velvet and Lyon 
Beans. Ann. Rpt. Florida Agr. Exp. Sta. 1911:82-108. 
1912. 
Castle, W. E., et al. 
Studies of inheritance in rabbits. Carnegie Tnst. of Wash- 
ington. Pub. 114 : 1-70. 1909. 
Heredity in relation to evolution and animal breeding. New 
York. Appleton, pp. 1-184. 1911. 
The inconstancy of unit characters. Amer. Nat. 46: 352-362. 
1912. 
East. E. M. 
The distinction between development and heredity. Amer. 
Nat. 43: 178-181. 1909. 
A Mendel i an interpretation of variation that is apparently 
continuous. Amer. Nat. 44:65-82. 1910. 
The Genotype hypothesis and hybridization. Amer. Nat. 
45 : 160-174. 1911. 
Bast, E. M., and Hayes, H. K. 
Inheritance in Maize. Bui. Connecticut Agr. Exp. Sta. 
167: 1-141 "Pi. 25. 1911. 
