and Laboratory Methods. 1117 



The herbarium contains nearly a milUon specimens, and is composed largely 

 of plants which have been subjected to critical study, and are consequently well 

 identified. Some very notable collections are embraced, and it is especially rich 

 in American forms, and in ferns, fungi, and mosses. In addition to being the 

 primary means of research bearing upon the natural affinities of plants, it is 

 invaluable as a reference collection in morphological studies. The herbarium 

 is increasing at the rate of fifty to a hundred thousand specimens annually. 



The living plants include the species native to the Garden tract, the intro- 

 duced forms from the temperate zone in the herbaceous grounds, pinetum, 

 fruticetum, arboretum, viticetura, nurseries and boundary plantations, and the 

 tropical and desert forms in the horticultural and propagating houses, amounting 

 to about six thousand species. 



Before beginning an investigation of any botanical subject it is of the greatest 

 importance that the worker should familiarize himself with its botanical history 

 to learn what other botanists may have written concerning it. To this end he 

 must search the volumes in the library. Periodicals, books, pamphlets, and 

 manuscripts must be examined, and the extent of known facts gotten well in 

 mind. The library of the Garden now contains nearly nine thousand volumes, 

 and is increasing at the rate of over fifteen hundred volumes annually. 



The facilities of the Garden are open only to students who have demonstrated 

 their ability to carry on independent research work, and no attention is given to 

 elementary instruction. The intending investigator, having complied with the 

 regulations of the institution and secured a table, is placed in consultation with 

 the member of the staff, or other attending botanists most familiar with the sub- 

 division of the subject in which his problem lies, from whom he receives only so 

 much help and advice as may be necessary to enable him to carry his work to a 

 successful end. The student is free to offer the results of his work in the form 

 of a thesis to any university at which he might become a candidate for a degree. 



The actual arrangement and extent of laboratory space and organization of 

 the equipment of the laboratories have been carefully worked out. The upper 

 floor of the museum building, with an area of nineteen thousand square feet, and 

 some special rooms in the basement, are devoted to research work. The library 

 is housed under the dome and in a stack room extension to the rear. The 

 physiological and morphological laboratories occupy the western end, and the 

 taxonomic laboratories and herbarium the eastern end. The laboratories include 

 a suite of fourteen rooms, giving separate facilities for work in the main divisions 

 of the subject. The equipment includes a supply of the apparatus necessary for 

 research. Microscopes of the most approved patterns of Bausch & Lomb, Leitz, 

 and Zeiss, with batteries of objectives of a wide range, are found to meet the 

 needs of the workers who have used the laboratories to this time. The photo- 

 graphic room contains professional stands with the best anastigmatic lenses of 

 Zeiss, Goerz, and Leitz, projecting and photomicrographic apparatus, field 

 cameras and accessories ; space is also afforded for the precision balances of 

 the chemical laboratories. The physiological dark-room is constant to tempera- 

 tures between 16° and 21 °C. The chemical laboratories are as yet only supplied 

 with the more elemental apparatus. The experimental room has an aquatic tank, 



