BULLETIN 39, UNITED STATES NATIONAL MUSEUM. [34] 



each sheet until the plant sought is reached. This would scarcely be 

 worth mentioning were it not for the fact, as every one will early find 

 out, that by far the greater part of the references to the herbarium will 

 be in search of species belonging to large genera. Very large genera 

 should be divided and kept in several genus-covers, and it is an excellent 

 plan to write on the outside the names of all the species in a genus cover. 



Upon the whole, then, it is doubtless best to mount the specimens 

 of the herbarium, but this should not be undertaken at first or until 

 considerable experience has rendered one skilled in selecting the very 

 best specimens both from a scientific and an artistic point of view. A 

 new beginner will never afterwards regret having waited at least three 

 years before mounting any of his plants. By this time he will have 

 seen many other herbariums and received the specimens of other older 

 botanists in exchange to compare with his own, and will then possess 

 some valuable ideas on the whole subject. This, therefore, though 

 probably the most complicated part of a botanist's work, is, when thus 

 viewed, the one upon which the least pains need be expended in de- 

 scribing the process, since if the proper course is pursued from the 

 beginning he will be sure to have already picked up nearly all the 

 needed information respecting it before he undertakes to apply it to 

 his own collection. 



The two principal methods of mounting may, however, be briefly de- 

 scribed. These are, first with glue and second with gummed strips. In 

 the first case ordinary fish or carriage glue may be employed with com- 

 plete satisfaction, since it may be used cold and thus avoid the neces- 

 sity of having appliances for heating as required by common glue. The 

 kind commonly sold as Le Page's Liquid Glue is in every way satisfac- 

 tory. The manipulator should be provided with a piece of common, 

 window glass a little larger than the ordinary herbarium pajjer. The 

 glue considerably thinned with cold water is to be spread in a thin layer 

 evenly over the glass and the plant laid gently down into the glue, 

 taking care to have all prominent parts touch the glue. The i^lant is 

 then lifted from the glass and placed carefully on the herbarium sheet, 

 which is ready at hand to receive it, and in the exact jiosition previously 

 determined to be the best. Each specimen should be first applied to 

 the white sheet on trial for this purpose. A dry cloth is then used to 

 remove any excess of glue that may have been spread on the paper, 

 and to press down any i)art of the plant that is inclined to lie badly j 

 the mounted sheet is laid down at one side, a few sheets of paper (news- 

 ipaper or brown paper) are laid upon it, and a board (a press-board will 

 do) is placed upon these. Another plant is then mounted in the same 

 manner, the board removed, the mounted plant placed on the j^apers 

 previously laid down, more papers put on this, and the board restored. 

 This process is repeated until all the plants are mounted. The mounted 

 sheets will be ready to place in the genus-covers the next day. When 

 the mounting is completed} the weight on the pile should be increased. 



