92 HANDBOOK OF MOSSES. 



expensive ; but some nice cells may be cut out of cardboard, 

 as follows : "Two punches, similar to those used for cutting 

 gun wads, are procured, of such sizes that with the smaller 

 may be cut out the centre of the larger, leaving a ring whose 

 side is not less than one-eighth of an inch wide. These rings 

 may be readily made, the only difficulty being to keep the 

 sides parallel, but a little care will make this easy enough. 

 For these cells a close-grained cardboard with a well-glazed 

 surface should be selected." The rings may be made to 

 form a cell any depth by placing one upon another ; and if 

 they are well soaked in gold size, they will permanently 

 adhere, and will be also rendered impervious to atmospheric 

 moisture.* 



The moss capsules to be mounted, assuming that several 

 are going to be placed in the same cell, are all cut the same 

 length, and fastened at the bottom of the cell with gum.f 

 My own plan is to fix one capsule on the glass slip, at the 

 bottom of the cell; and when this is firmly fixed, to build 

 any other capsules I may wish to place in the cell around 

 this. After allowing the gum to become quite dry, I then 

 place on the top of the cell one of the round glass covers, 

 and fasten this down with the white zinc varnish or gold 

 size. It is often somewhat difficult to remove the opercu- 

 lums when the capsules are old and dry ; but I have found 

 that by placing these capsules in some hot water for a few 

 hours, I could then readily remove the operculum with either 

 one of the triangular needles mentioned before or with my 

 dissecting knife. Of course, these capsules must be allowed 

 to dry thoroughly before they are placed in tfye cell, and the 

 spores should be removed from the inside of the capsule, 

 else they will be found a constant trouble later on. 



A good representative slide should have a capsule 

 mounted with the operculum on to show its character ; the 



* One of these cells, made as above, should be fixed to the glass slip 

 with gold size, and allowed to become properly dried before being used ; 

 this will then form a neat cell. 



t A mixture of equal parts of gum arable and gum tragacanth is best 

 as this makes an opaque fixing agent. 



