LESSON 34.] AND FORM AN HERBARIUM. 201 



which for most plants requires about a week ; then they may be 

 transferred to the sheets of paper in which they are to be preserved. 

 If a great abundance of drying-paper is used, it is not necessary 

 to change the sheets every day, after the first day or two. 



585. Herbarium, The botanist's collection of dried specimens, 

 ticketed with their names, place, and time of collection, and sys- 

 tematically arranged under their genera, orders, &c., forms a Hor- 

 tus Siccus or Herbarium. It comprises not only the specimens 

 which the proprietor has himself collected, but those which he ac- 

 quires through friendly exchanges with distant botanists, or in other 

 ways. The specimens of an herbarium may be kept in folded sheet? 

 of neat, and rather thick, white paper ; or they may be fastened on 

 half-sheets of such paper, either by slips of gummed paper, or by 

 glue applied to the specimens themselves. Each sheet should be 

 appropriated to one species ; two or more different plants should 

 never be attached to the same sheet. The generic and specific 

 name of the plant should be added to the lower right-hand corner, 

 eilher written on the sheet, or on a ticket pasted down at that corner; 

 and the time of collection, the locality, the color of the flowers, and 

 any other information which the specimens themselves do not afford, 

 should be duly recorded upon the sheet or the ticket. The sheets 

 of the herbarium should all be of exactly the same dimensions. The 

 herbarium of Linnaeus is on paper of the common foolscap size, about 

 eleven inches long and seven wide. But this is too small for an 

 herbarium of any magnitude. Sixteen and a half inches by ten 

 and a half, or eleven and a half inches, is an approved size. 



586. The sheets containing the species of each genus are to be 

 placed in genus-covers, made of a full sheet of thick, colored paper 

 (such as the strongest Manilla-hemp paper), which fold to the same 

 dimensions as the species-sheet ; and the name of the genus is to be 

 written on one of the lower corners. These are to be arranged 

 under the orders to which they belong, and the whole kept in closed 

 cases or cabinets, either laid flat in compartments, like large "pigeon- 

 holes," or else placed in thick portfolios, arranged like folio volumes, 

 and having the names of the orders lettered on the back. 



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