LICHENS AND THE NATURALIST. 67 



layer of lichens, and continue this process until the 

 entire collection of fruticose and foliose lichens is 

 placed between dryers. On top of the entire pile 

 place a board with a weight of from 20 to 25 pounds. ^ 

 For the first two days the specimens with the two 

 sheets of newspaper should be transferred to dry dryers 

 twice daily. For this purpose it is necessary to have 

 two sets of dryers ; the moist ones should be exposed 

 to the sun while the others are in use. For the next 

 three days they need be changed only once daily. At - 

 the end of five days the lichens are, no doubt, perfectly 

 dry; they will be found permanently flattened and 

 ready for mounting. 



Lichens, like all other botanical specimens, should 

 be mounted on the regulation mounting sheets of • 

 heavy glazed white paper. Fasten the specimens to 

 the paper by means of glue (fish-glue). Arrange the 

 specimens uniformily, but never place more than one 

 species on a sheet. With foliose lichens, it is desirable 

 to place two specimens side by side, one showing the . - 

 lower surface and the other the upper surface. If the 

 specimens are large, one will be enough to place on a 

 sheet ; if small, as many as five or six may be glued on. 

 In this case it is advisable to select specimens from 

 widely different latitudes and altitudes. 



As soon as the specimens are glued on the sheets 

 they should again be placed between the sheets of . ^ 

 newspaper and dryers, with pressure applied until the 

 glue is perfectly dry, when they are ready to be placed 

 in the herbarium with other specimens. 



If mounting paper is not at hand, the specimen may 



