170 JOURNAL OF THE ARNOLD ARBORETUM [vol. hi 



trees 



of the world than can now be found here. Such information can be ob- 

 tained only in small part by correspondence and the information which the 

 Arboretum needs can only be successfully obtained by agents sent out to 

 obtain it. It is desirable that the work which the Arboretum has begun 

 in eastern continental Asia should be continued and if possible completed. 

 The flora of the coastal region north of latitude 45, including Kamtschatka, 

 is still very imperfectly known. From this region trees and shrubs, still 

 unknown in gardens, which will grow in New England can probably be 

 obtained. Explorations in the northern part of Kansu, the great northwest 

 province of China, may also be expected to enrich northern gardens. The 

 flora of China south of the Yang-tze-kiang River and east of the Poyang 

 Lake is still little known; and the trees of Cochinchina (Tonkin, Annam 

 and Siam) are still badly represented in the Arboretum herbarium; and 

 Harvard College will not have fulfilled its agreement with the Arnold 

 Trustees until it has caused to be explored through the Arboretum the 

 forests which cover the ranges of the Altai Mountains which form the 

 southern boundary of central Siberia and the great interior region south of 

 these mountains. 



If the Arboretum is to become a great institution for gathering and 

 spreading information about trees and allied plants specimens and a series 

 of photographs of every species of tree in the world should be found in its 

 herbarium. The work which it has accomplished in its first fifty years in 

 North America and the Japanese Empire should be extended over the rest 

 of the world. For the trees of the tropics this is now important as tropical 

 forests are fast disappearing to make room for plantations of rubber-pro- 

 ducing and other economic plants. The best soil is selected for these 

 plantations, and as with few exceptions the largest and best individuals of a 

 species are produced in the best soil, many species, or certainly their best 

 representatives, must disappear, and in the future the student of trees must 

 depend for any knowledge of many trees on the material and information 

 preserved in institutions like the Arnold Arboretum. The exploration of 

 the tropical forests of the world will require perhaps a century and a large 

 expenditure of money to accomplish. It is work that this Arboretum 

 should begin and steadily push forward. 



Second: The Arboretum requires a properly equipped department for 

 the study of the diseases of trees in this country and in other parts of the 

 wor 1 d . 



Third: The Arboretum requires a department in which the study of 

 insects dangerous to trees and the methods for their control can be carried 

 on in connection with the other investigations undertaken by the Arbore- 

 tum and controlled by it. 



Fourth: The Arboretum needs a department for the breeding of new 

 races of plants. The world already owes much to the intelligence and skill of 

 the plant breeder. He has increased the value of many farm crops and has 



