BREEDING FOR DISEASE RESISTANCE IN PLANTS 283 
If commerce in living plants is so dangerous, what view shall be 
taken of governmental plant introductions? The Office of Seed and 
Plant Introduction brings in seeds and plants from all over the world 
in small lots of a few seeds or buds each of thousands of species. If 
these introductions can be kept free from disease, and they have been 
thus far, they will be of invaluable assistance to the breeder. The 
great need is for a better organized use of this plant introduction 
service to bring in not only all the varieties of a crop but all its relatives 
that can be crossed with it, and, after propagation in a quarantine 
station, to place them at the disposal of breeders. 
The improvement of our staple crops itself requires co-operative 
organization to conduct on a broader scale with ample material the 
work now attempted in an individual way. There is need of more 
systematic foreign exploration by specialists on the crops to be bred, 
who should in all cases be accompanied by pathologists to study 
the diseases that occur in the regions from which introductions are 
contemplated, and to assist in the collection of disease-free material. 
Foreign testing and propagation stations are also needed, the last to 
insure the sending of material free from insects and diseases. 
LITERATURE CITED 
1. Norton, J. B. Methods used in Breeding Asparagus for Rust Resistance. U. S. 
Dept. Agr. Bur. PI. Ind. Bull. 263. 1913. 
2. Orton, W. A. The Development of Disease-resistant Varieties of Plants. Con- 
ference Internationale de Genetique 4: 247-265. Paris. 1911. 
3. Jones, L. R., and Oilman, J. C. The Control of Cabbage Yellows through Disease 
Resistance. Wis. Agr. Exp. Sta. Res, Bull. 38. 1915. 
4. Bolley, H. L. Flax Culture. N. Dak. Exp. Sta. Bull. 71: 212. 1906. 
5. Johnson, James. Resistance in Tobacco to the Root-rot Disease. Phytopathology 
6: 167-181. 1916. 
