90 HANDBOOK OF MOSSES. 



contained in the leaf-cells, etc. This boiling does not 

 injure the mosses, and will be always found necessary in 

 such mosses as the Sphagnums. If the moss be a small 

 one, such as one of the Phascums or a small Dicranella, it is 

 well to mount the specimen whole, with all the various parts 

 displayed, such as capsule, operculum, calyptra, etc. But it 

 is always necessary to have one or two leaves carefully dis- 

 sected away from the stems, so as to show their structure, 

 the form and nature of the leaf-cells, the margination, i.e. 

 entire or serrate on the margin, the shape of the base and 

 the character of the cells at the base, a matter often of great 

 importance. This may readily be done if the stem be cut 

 through immediately below the base of the leaf, with a small 

 knife or one of the triangular needles such as are used by 

 glovers ; the leaf should then be turned back and detached 

 from the stem. In the Hypnums and other pleurocarpous 

 mosses it is necessary to have perfect leaves from the stem 

 as well as from the branches, as the character of the stem- 

 leaves is always of importance in the diagnosis of the 

 species. Some also of the perichsetial leaves are also added, 

 these are the leaves immediately around the base of the fruit- 

 stalk, also the lower portion of the fruit-stalk divested of 

 the perichaetial leaves, to show the character of the vaginule. 

 This is of special value in some mosses, as in the Ortho- 

 trichums. The capsule with the operculum on, and with it 

 removed, may also be added, so as to show the presence or 

 absence of the peristome and annulus, the character of the 

 operculum or lid, whether conical, rostrate, etc. All these 

 parts are then placed on a clean glass slip, and mounted 

 in glycerine jelly, Deane's gelatine, or glycerine pure and 

 simple.* 



Before, however, mounting the specimen in either gly- 



* It may here be mentioned that in some instances, i.e. where the 

 leaf-cells of the moss are very dense, such as the Andreseas or the 

 Grimmias, these cells may be made more distinct and their character 

 more fully displayed if the leaves be placed for a short time in a heated 

 solution of dilute liq. potass or liq. soda ; but leaves so treated must be 

 thoroughly washed afterwards in clean water, to remove all traces of 

 the re-agent, before being mounted. 



