FLORA OF WASHINGTON AND VICINITY. 235 



7. — General, remarks on herbarium work. 



The herbarium is a perpetual growth. Every summer specimens of 

 your own collecting are added to it, and every winter still more are 

 received through exchange. Nothing ever goes out, but accessions are 

 constantly being made. It is therefore very important to keep a strict 

 account with it. You want to know at any moment not only what you 

 have, but how many you have. If asked how large your herbarium is, 

 you want to be able to answer by a glance at your account — 4,000, or 

 whatever number of species it actually contains. You also want, if any 

 one asks you whether you have such and such a plant, to be able to reply, if 

 not from memory, which, of course, is not always possible, by a moment's 

 looking at something besides the specimens. 



Very little herbarium work can generally be done during the collecting 

 season. It is often necessary, and perhaps best, not to attempt to distri- 

 bute current collections. After the season is over the plants collected and 

 preserved during the summer are first all arranged in botanical order j 

 then, beginning at the first, they are placed in two general sets, which your 

 notes and lists enable you to make, one of which contains only new, i. e., 

 unmounted plants, and the other, specimens of species already mounted. 

 With regard to the first of these sets, of course your duty is simple; 

 they must be mounted and go to swell the general collection. But as 

 to the second, it will by no means do rashly to class them as dupli- 

 cates and as such put them away. Everj' one should be carefully com- 

 pared with what you have previously collected. So rapid will be your 

 improvement in making good specimens that you will be surprised often- 

 times that you should have considered the one previously put away a 

 good one. If, then, you have had the patience to refrain from mount- 

 ing the earlier ones, it will be no trouble to substitute the later and 

 better one. But in many cases where the first specimens were good 

 this comparison will enable you to supply missing forms and states 

 and help to render the herbarium perfect. After all such have been 

 thus compared and the specimens or parts needed for the herbarium 

 have been taken out for mounting, the remainder will constitute true 

 duplicates to be added to your list of duplicates, and put away in their 

 proper order in that department. 



Next, as regards the winter accessions. Unavoidably there will come 

 in packages by exchange a good many i)lants that you already have in 

 your herbarium. These should be compared as above described, but, 

 as already remarked, if from other localities than any you have, they 



