[33] DIRECTIONS FOE COLLECTING PLANTS KNOWLTON. . 



written ou auotber. The principal objectiou to this system is that it 

 requires time and trouble to remove the order-covers every time a plant 

 is wanted. Ui)on the whole, it is jierhaps better to do without order- 

 covers entirely until the herbarium becomes quite large and complete. 

 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 botauically^, 

 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 a 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 can not 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 suffice. 



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 placed 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 paj^er. 



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

 cially 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 a book. 

 It is held in t4ie two hands, with the right (open) edge elevated at an 

 angle of about 45° from the table, aud while the two thumbs rapidly 

 separate the edges of the sheets from the upper towards the lower ones 

 the eye glances at each label attached to the lower right-hand corner of 

 28323— Bull. 39, Pt. B 3 



