OF THE HERBARIUM. 170 



must, first of all, decide whether the preparation is suf- 

 ficiently thin and flat to be laid between the sheets of the 

 herbarium, or whether it must be kept in a separate 

 cabinet, like a specimen of mineralogy. 



A large number, those which have a crustaceous thallus, 

 and others which are not attached to their support by their 

 whole circumference, may be disposed of in the first 

 mentioned way ; care being taken that the stone or wood 

 be made as thin as is compatible with the safe keeping of 

 the epiphyte : to prevent any undue pressure between 

 neighbours, they should be placed by the side of, not 

 exactly over, each other. Certain, however, of the gymno- 

 carpous section (like Calycium and Coniocybe), which are 

 characterised by stalked apothecia, would be spoiled, if 

 their safety was not better cared for. These should be 

 deposited in chip or pasteboard boxes with covers, or they 

 may be fastened on cardboard, with strips of wood, gummed 

 on each side, of sufficient thickness to keep the specimen 

 from being rubbed : a piece of cardboard laid on the 

 wooden strips will still further ensure its integrity ; it may 

 then be laid between the pages of a wrapper, as usual.* 



In very large collections coarse solid objects, such as 

 stones, which have been encrusted by Lichens, should be 

 put away in drawers and boxes, apart from the herbarium. 

 At the same time, as their absence necessarily causes a 

 gap in the systematic arrangement of the specimens, it is 

 well to deposit in the place, which should have been 

 occupied by the Lichen, an empty sheet of the wrapping 

 paper with a label, which bears on its face the name of 

 the missing species, and the number, with which it is 

 ticketed in the drawer. 



The same mode of proceeding may be adopted with 



* All adhesive materials, as gum, &c, should be first poisoned by 

 an infusion of corrosive sublimate ; or a small quantity of some 

 essential oil should be mixed with them. This prevents the growth 

 of Fungi, and the attacks of insects.— Ed. 



n2 



