290 FUNGI. 



are an acquisition, and may be secured in the following manner. 

 After the fungus has been soaked in water, where that is neces- 

 sary, and the hymenium extracted on the point of a penknife, let 

 it be transferred to the centre of a clean glass slide. A drop of 

 glycerine is let fall upon this nucleus, then the covering glass 

 placed over it. A slight pressure will flatten the object and expel 

 all the superfluous glycerine around the edges of the covering 

 glass. A spring clip holds the cover in position, whilst a camel- 

 hair pencil is used to remove the glycerine which may have been 

 expelled. This done, the edges of the cover may be fixed to the 

 slide by painting round with gum-dammar dissolved in benzole. 

 In from twelve to twenty-four hours the spring clip may be 

 removed, and the mount placed in the cabinet. Glycerine is, 

 perhaps, the best medium for mounting the majority of these 

 objects, and when dammar and benzole are used for fixing, there 

 is no difficulty experienced, as is the case with Canada balsam, 

 if the superfluous glycerine is not wholly washed away. Speci- 

 mens of Puccinia mounted in this way when fresh gathered, 

 and before any shrivelling had taken place, are as plump and 

 natural in our cabinet as they were when collected six or seven 

 years ago. 



Moulds are always troublesome to preserve in a herbarium in 

 a state sufficiently perfect for reference after a few years. We 

 have found it an excellent method to provide some thin plates of 

 mica, the thinner the better, of a uniform size, say two inches 

 square, or even less. Between two of these plates of mica 

 enclose a fragment of the mould, taking care not to move one 

 plate over the other after the mould is placed. Fix the plates 

 by a clip, whilst strips of- paper are gummed or pasted over the 

 edges of the mica plates so as to hold them together. When 

 dry, the clip may be removed, and 'the name written on the 

 paper. These mounts may be put each in a small envelope, and 

 fastened down in the herbarium. Whenever an examination is 

 required, the object, being already dry-mounted, may at once be 

 placed under the microscope. In this manner the mode of 

 attachment of the spores can be seen, but if mounted in fluid 

 they are at once detached; and if the moulds are only preserved 



