168 proceedings: botanical society 



genera was it properly placed, since it is closely related to true citrous 

 fruits and will hybridize with the cultivated forms. Not cursory in- 

 spection of botanical literature, but protracted critical study of the botan- 

 ical relationships, was necessary to make plain the desirability of the 

 introduction of this species for the successful breeding of hardy and 

 drouth-resistant citrous fruits. Plants not so closely related to the 

 cultivated forms have been found useful stocks upon which to graft 

 cultivated varieties. A properly digested taxonomic knowledge of the 

 wild relatives of our cultivated plants was found to be indispensable 

 as a foundation for all efficient plant introduction and plant breeding. 



The introduction of foreign plant diseases: R. Kent Beattie. 

 American agriculture has been based largely on introduced plants. 

 Only twelve of the two hundred and forty-seven species of cultivated 

 plants studied by De Candolle in his Origin of Cultivated Plants are 

 clearly indigenous to the United States., Diseases of American eco- 

 nomic plants may be separated into two groups: (1) Those which have 

 passed from native plants to the introduced hosts, such as pear blight; 

 (2) Those which have been introduced, such as citrous canker and 

 the chestnut bark disease. Plant disease may be introduced in three 

 ways: (1) The diseased crop plant may be imported for commercial 

 use; (2) The diseased crop plant may be imported for scientific pur- 

 poses; (3) The spores of the disease-producing organism may be brought 

 in on plants not affected by the disease. 



Commercial plant introduction, except field crops and florist stock, 

 has been under a system of permit and inspection. In most states, 

 however, the inspectors were trained as entomologists rather than 

 pathologists, and there has been little restriction on the commercial 

 importation of fungus plant diseases, except in the case of specifically 

 quarantined crops. Material imported by the U. S. Department of 

 Agriculture has undergone rigid inspection and plants which show 

 symptoms of disease or arouse suspicion have been treated or grown 

 under restraint until danger was passed. During the year 1916 the 

 Pathological Inpectors of the Federal Horticultural Board while ex- 

 amining the material imported by the U. S. Department of Agriculture 

 found one hundred and sixty-three hosts affected with disease and de- 

 termined one hundred and fifty-seven diseases on these .hosts. 



The protection and propagation of plant introductions: B. T. Gal- 

 loway. The rapid change in public sentiment in the matter of plant 

 sanitation and plant hygiene and the need for a -constructive policy 

 in the matter of adequately protecting our crop plants, and at the 

 same time not closing the doors to the development of new crop in- 

 dustries through the introduction of plant immigrants, was discussed. 



The Office of Foreign Seed and Plant Introduction in the Depart- 

 ment of Agriculture has received seeds and plants from all over the 

 world. These seeds and plants were grown, propagated, and tested 

 at four outlying stations. It has also acted as the agent for handling 

 seeds and plants from foreign countries for other branches of the De- 

 partment, for the experiment stations, and for many private and pro- 



