THE PRESERVING OF PLANTS 115 



1506. Specimens are usually mounted on single sheets of white 

 paper of the stiffness of very heavy writing-paper or thin Bristol- 

 board. The standard size of sheet is 11% x 16% inches. The plants 

 may be pasted down permanently and entirely to the sheet, or they 

 may be held on by strips of gummed paper (as in Fig. 436). In the 

 former case, Dennison's fish-glue is a good material to use.- Only 

 one species or variety should be placed on a sheet. Specimens 

 which are taller than the length of a sheet should be doubled over 

 when they are pressed. The species of a genus are collected into 

 a genus cover. This cover is a folded sheet of heavy manila or 

 other firm paper, and the standard size, when folded, is 12 x 16% 

 inches. On the lower left-hand corner of this cover the name of 

 the genus is written. The specimens are now ready to be filed 

 away. If insects attack the specimens, they may be destroyed by 

 fumes of bisulphide of carbon (which is very inflammable) or chloro- 

 form. In this case it is necessary to place the specimens in a 

 tight box and then insert the liquid. Lumps of camphor placed 

 in the cabinet are useful in keeping away insects. Those who 

 wish detailed information on the collecting of plants should con- 

 sult W. W. Bailey's "Botanical Collector's Handbook." For 

 methods of making leaf prints and of preserving flowers in nat- 

 ural colors (and of collecting and preserving insects), consult 

 Chap. XV. of Bailey's "Horticulturist's Rule-Book," 4th edition. 



.150c. The naming of the specimens must be accomplished with 

 the aid of some manual of the plants of the region. There are 

 several books to aid in this work; but the teacher should bear in 

 mind the important fact that the name of a plant is less impor- 

 tant than the plant itself, and effort should not be expended in this 

 direction at the expense of the study of the specimens. By mak- 

 ing herbaria of the various forms of common species of plants, 

 much of the labor of mere identification is avoided. The name of 

 a plant serves two purposes: it affords language which we can use 

 in speaking or writing of the plant, and it serves as an index 

 to whatever may have been written about the plant. 



150f(. The standard systematic work upon the plants of North 

 America is Gray's "Synoptical Flora," which, however, is not yet 

 completed. For that part of the United States east of the Mis- 

 sissippi and north of Tennessee, and practically including adjacent 

 Canada, Gray's "Manual," now in its sixth edition, is the standard 



