8 



jiblc to tlie cultivation of tlie European grape and tlie orange. Australia 

 is largely dependent upon lier fields of grain and lier growing fruit 

 trade. Her native food plants play no important part in lier develop- 

 ment. The wealth of Ceylon and Java is reaped largely from the 

 cultivation of five or more exotic species, the Chinese and Assam teas, 

 the Peruvian cinchona, and the Arabian and Liberian coffees. South 

 African civilization, from an agricultural standpoint, is not causally 

 connected with the development of any native plant T)roduct. So thor- 

 oughly has this fact been recognized by all colonizing nations that they 

 have established botanic gardens in their new colonies, one important 

 function of which is to secure and distribute exotic economic plants 

 thronghout^the colony. 



Such work of introduction has been carried on by the Department of 

 Agriculture for many years, and though it is not within the province of 

 this bulletin to x)oint out the beneflLS accruing from the introductions 

 made, notably by Mr. William Saunders, Chief of the Division of Gar- 

 dens and Grounds, the Pomological Division, the Division of Agros- 

 tology, and the Seed Division, it may be remarked that the orange 

 growers of California expressed their appreciation of Mr. Saunders's 

 effort when thej' said the introduction of the Bahia or Washington 

 navel orange had been worth more to the growers of California than 

 the total cost of maintaining the Department of Agriculture since its 

 inception. 



It is the purpose of this bulletin to point out briefly some of the fac- 

 tors which should govern the work of plant introduction and to make 

 clear, if possible, the new aspect revealed by recent progress in i)lant 

 breeding and plant pathology. 



The rapidly growing interest in the work of plant hybridization and 

 selection and the increasing demands for species of plants to be used 

 in the amelioration of those already in cultivation, open ui) new fields 

 for legitimate plant introduction, while the recognition of the great 

 losses caused by parasitic insects and fungi emphasize the importance 

 of the most careful supervision and inspection of all imi:)orted plants.* 



■■ The introduction of material for forest planting does not present all the problems 

 ■whicli attend tlie introduction and improYemeut of fruits. Kor is it of the same 

 importance or as full of promise. Moreover, the United States possesses in its forest 

 flora snch a wealth and variety of valuable species that there is little call for increas- 

 ing the number, at least in the forest regions and for the present, when ^xe have 

 hardly yet begun to be accinainted Tvith the possibilities of our own species and 

 with the necessity of method in their proiiagation. 



There is, to be sure, no objection even now to beginning the testing of exotics, for 

 with a crop which matures in a century or so the results of such tests are long in 

 coming, and hence a timely begiuniug is called for. If the German foresters had 

 known what they will know within the next decade regarding our white pine and 

 other conifers they would have used them more extensively than they did a hundred 

 years ago. On the other hand, we should long ago have engaged in the planting of 

 the cork oak for the sake of our growing wine industry, since through the importa- 

 tions by the Department some thirty years ago, and again through the Division of 



