230 FLORA OF WASHINGTON AND VICINITY. 



done, this objection need not liave great weight. On the other hand, it 

 has this important scientific advantage, that if mistakes are made the 

 X)lants may be taken off, and if very essential they may be removed 

 uninjured, turned over, or studied. With many botanists these con- 

 siderations preponderate largely, and it is probable that they come to 

 have more and more weight as experience points out the defects of the 

 glue system. For small or private herbariums, therefore, the strip sys- 

 tem is, I think, ui)ou the whole, to be preferred. 



In mounting plants, by whatever method, a few precautions will l3e 

 necessary. The majority of specimens are small enough to admit of 

 putting two or more on a sheet. Unless very small, no two from the 

 same locality should be mounted together, except where they differ in 

 some imi>ortant respect, which it is desired to show. But a sheet is 

 vastly improved where specimens of the same plant, from widely vary- 

 ing localities, are grouped together upon it. In the course of a botanist's 

 travels and exchanges, he will obtain duplicates of this kind. Some seem 

 to have an idea that if they have a plant, no matter from what source 

 this is suf8cient; but a herbarium consisting of only one specimen of 

 each species would be next to A^aluless, though it should thus embrace a 

 large part of the flora of the country" or the globe. Instead of putting 

 everything into the duplicates of which you happen to have a representa- 

 tive, it should first be ascertained whether a new plant is from a different 

 locality from that of any you already have mounted; if so, mount it at all 

 events, and if possible on the same sheet. The first specimen mounted 

 on a sheet ought to go on the right-hand side, so that its label will 

 naturally occupy the lower right-hand corner. Without crowding it 

 out too near the margin, care should be taken not to waste space by 

 lJutting it too near the middle so as to prevent another specimen from 

 being mounted on the left of it. If lacking in any of the i:)articulars 

 which should be represented, and can be obtained from the local flora, 

 such as fruit or radical leaves, these should be procured and added to the 

 sheet before specimens from other localities are given a place. The date, 

 etc., of collecting these additional parts should be added to the label^ 

 or if they seem to require it, a new label may be written for them. 

 Where only two specimens fill a sheet, one of the labels should occupy 

 the right and the other the left corner ; if three go on, the third label 

 may occu])y the middle of the lower edge of the sheet. In the case of 

 very small plants, several specimens are needed properly to represent 

 each plant. The lower half of the sheet may first be occupied and after- 



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