BOTANICAL GARDENS 949 



lists of plants offered in exchange, guides to the museum and conserva- 

 tories, and finally monthly and other periodicals, embodying the results of 

 research, and other matters pertaining to the advancement of botany or 

 the organization of the institution. 



5 . Courses of lectures and instruction to organized classes. This is one 

 of the latest and most important educational developments of botanic 

 gardens. Regular courses were offered to medical students as early as 

 1829, in the Chelsea Physic Garden (England), and this has now become 

 an important phase of activity, especially of all gardens connected in any 

 way with educational institutions. In fact didactic instruction by botanic 

 gardens has developed parallel with the growing tendency to establish 

 them in connection with universities or other educational institutions. In 

 earliest and later private gardens, practically no attention was given to 

 teaching. In the physical gardens of apothecaries' societies and schools of 

 medicine, the teaching was confined to the nature and properties of medic- 

 inal plants, but with the organization of university gardens and gardens 

 closely articulating with institutions of learning, was introduced formal 

 instruction of classes in various phases of pure and applied botany. 



6. Docentry. Docentry is a comparatively new idea in education and 

 is confined to institutions devoting a considerable portion of time to the 

 popularizing of knowledge. So far as the writer knows, the New York 

 Botanical Garden was the first botanical garden employing docentry. The 

 former system, here as in most other gardens, was that of personal guides 

 for visitors who apply, and aids and gardeners were detailed for this pur- 

 pose. Under the new system there is a regularly appointed 'docent,' who 

 leaves the front door of the museum building every week-day afternoon at 

 three o'clock, with a definite route for each day. Parties may start with 

 the docent, or he may in turn meet with two or three interested visitors, 

 volunteer interesting information concerning the trees and other plants of 

 the collections, and thus assemble an extempore class. " 



ELEMENTS OF THE DESIGN OF A BOTANIC GARDEN 



Selection of Site. 



In selecting a site for a botanical garden the following factors may be 

 considered : 



1. The site should be far enough removed from the environment of a 

 city to escape the deleterious effects of dust, smoke and poisonous gases 

 upon the plants. By taking account of prevailing winds and the location 

 of the principal centers of transportation and manufacturing it might be 

 quite possible to locate and successfully conduct a botanical garden fairly 

 close to the center of population; but on the whole a site, which from the 

 standpoint of atmospheric conditions more nearly approximates the open 

 country, is to be desired. 



2. Topographically it is desirable, especially for large gardens, to secure 

 a site possessing a diversity of elevations and natural forms such as hills, 



