236 FLORA OF WASHINGTON AND VICINITY. 



should be mounted. It will not do, however, to mount them without 

 comparison with those on hand, for in the majority of cases your sheet 

 will not be full and the new plant can be added to it, which, aside from 

 the question of economy, is far more scientific than to have them on 

 separate sheets. 



Not only with regard to summer, but to all winter accessions, the 

 number added should be carefully noted and footed into the running 

 account, so that the whole number in the herbarium may be at all times 

 known. It is more difficult to have easy access to any name and be 

 able to say with certainty whether you have it or not. Some merely 

 mark their books and catalogues where the plants are enumerated and 

 depend upon finding them in this way, but this is a clumsy method, not 

 to be recommended. If there is a large comprehensive check-list, like 

 Mami'S Catalogue, it is well to devote one to this purpose, and so far as 

 the plants there enumerated are concerned, this will show whether you 

 have them or not. But you will be sure in time to get plants not found 

 in any such check-list. Of course lists of such can be kept, and 

 should be, but eventually they will become inconvenient. Plants will 

 reach you of which no book in your library, and none accessible to you, 

 contains a description. What shall be done with these? After a great 

 amount of trouble of this kind I have found myself driven at last to the 

 adoption of the card-catalogue system for my entire herbarium, and so 

 charmingly does it work that I do not hesitate to commend it to the pro- 

 fession, and to advise beginners to commence with it and keep it up. 

 This perhaps need scarcely be described, but I may briefly say that it 

 consists of a drawer of cards, alphabetically arranged, on which are writ- 

 ten the names of all the plants in the herbarium. All necessary details 

 may be obtained by a visit to any large library and an inspection of its 

 card system. 



When a package of plants is received, or in any way comes up for 

 final disposition, it is opened and the first specimen is examined. If 

 already represented in the herbarium, it is put into the pile to be com- 

 pared. If there be any doubt, the cards are consulted; if not found, a 

 card is immediately written and slipped into its place in the drawer: the 

 plant is then placed in the package to be mounted. In this way no new 

 plant ever finds its way into the herbarium without its card having been 

 first added to the card-catalogue. 



The vast multiplicity of different objects to be handled in making a 

 herbarium, and the variety of ways in which they require to be disposed 



