226 FLORA OF WASHINGTON AND VICINITY. 



order-covers entirely until the herbarium becomes quite large and com- 

 plete. If the plants are kept in the natural order, you will soon become 

 so familiar with it that you will know within one or two partitions 

 where any plant is at any time. 



It is not a mere accident that I have mentioned the general character 

 of the herbarium before mentioning the important process of mounting 

 plants. This is the finishing stroke of the whole work and should not 

 be hastily rushed into. A plant once mounted is generally fixed for all 

 time, and this should presuppose that it is not only known botanically, 

 but approved as a suitable specimen to adorn a cabinet. If rare, and 

 not likely to be found again, of course it should be mounted, even though 

 in itself imperfect, but in so far as the local flora is concerned, this is 

 very seldom the case. 



For these and other reasons I would advise the postponement of the 

 work of mounting until after considerable experience has been acquired 

 in collecting and in general herbarium work. Some botanists never 

 mount plants. They urge with considerable force that this renders 

 them incapable of further study or examination, which any plant is 

 always liable to require. A specimen once mounted cannot be turned 

 over for the purpose of seeing the other side, where the two sides differ, 

 as is generally the case. To meet this objection, such plants when 

 mounted must be in duplicate, or so much so as to exhibit both sur- 

 faces. In the case of ferns, for example, nothing less than the mount- 

 ing of two entire specimens will generally sufiice. 



Plants may be nicely kept without mounting by placing them in 

 double sheets of ordinary paper, and these in genus-covers the same 

 as if mounted. For increased safety, the fold of the species-cover may 

 be placed in the reverse position to that of the genus-cover. The name 

 of the species may then be written on the species-cover or on a white 

 slip and pasted on the outside of it, to save opening any that you 

 may not wish to examine. No two species should ever be i)laced in the 

 same cover, and where it is desired to preserve several specimens of the 

 same species these may go inside the species-cover on separate sheets of 

 paper. 



The objection to this plan as a final one is that much handling, espec- 

 ially after the specimens become old, breaks them up and destroys 

 them. It is also more trouble and requires more time to open the 

 species-covers than to look at the mounted page. In the latter case 

 there is a quick method of looking a large genus through as you would 



