HARDWICKE'S SCIENCE-GOSSIP. 



ON MOUNTING MICRO-FUNGI. 



AS the seasons of the year revolve in rapid succes- 

 ' sion, each, and all, bring with them their own 

 particular work and studies ^for the microscopist. 

 When, as Horace puts it, " Solvitur acris litems grata 

 vice veris et luivo/ii," the ardent microscopist begins 

 to prepare for his early campaign, over hill, through 

 dale, and in the woodlands ; again, when summer 

 bursts upon him with all her warmth and beauty, he 

 plunges deeper than ever in scientific research for 

 objects dear to his own particular branch of study ; 

 autumn, too, finds him busily engaged wandering 

 through fields lit up with the brilliance of the golden 

 grain soon to be ingathered. At last comes winter, 

 "clothed all in frieze," this is without doubt the 

 season of all others when study and manipulation of 

 his objects collected in the bright seasons are brought 

 more particularly into play. Within his study, with 

 his microscope and objects at hand, cheered by the 

 friendly blaze and warmth of his own fireside, he feels 

 that the dull dark months, as some consider them, are 

 to him anything but dark and dreary. To such a 

 time we have once more come, and to each and all it 

 has brought its delightful work. My own particular 

 study throughout this year has been the micro-fungi, 

 those minute organisms which live on other plants. 

 It is my intention therefore in this short paper to 

 put before my readers, as briefly and as concisely as 

 possible, a few brief hints, culled from my own ex- 

 perience, as to the best and the easiest way of 

 mounting those micro-fungi for which we have made 

 so diligent a search throughout the spring, summer, 

 and autumn months, with, let us hope, plenty of 

 success. I do not intend to enter into the minutiae of 

 collecting the fungi and classing them. To those who 

 at present have not taken to this most interesting 

 branch of microscopical research, let me recommend 

 a book which will give them all the knowledge on the 

 head of collecting and classing they will require ; I 

 mean " Rust, Smut, Mildew, and Mould," by 

 Dr. M. C. Cooke, a book to whose value and excel- 

 lence all who, like myself, have used it and (let us 

 hope) profited by it will, I feel sure, bear witness. 



The mounting of micro-fungi is very simple, and 

 may be classed under two heads : — 



1st. Those specimens which may be mounted dry. 



2ndly. Those which require some medium in which 

 to be preserved. 



And, firstly, of the apparatus required for dry 

 mounting : — 



1. Plenty of glass slips with ground edges.* 



2. Thin glass circles of various sizes. 



3. Three or four dozen vulcanite haiL,. 



4. Sharp fine scissors (a pair). 



• *, Gr ° und ed S e sli ps, though more expensive, are the cheaper 

 in the long-run, as they are neater and of smaller compass. 



5. Bottle of white-lead varnish. 



6. Turn-table and camel's-hair brushes. 



All these things being at hand, we may proceed to 

 manipulate our fungi. Of course, the great Order 

 from which so many dry mounts are taken are the 

 /Ecidiacei ; we will suppose that we are about to 

 mount a specimen of M. Tussilaginis. First, take the 

 leaf on which the specimen is located, and with the 

 fine scissors cut round the cluster-cup, leaving suffi- 

 cient leaf to fill up the vulcanite cell. Having taken 

 care that the specimen lies perfectly flat in the field, 

 place a ring of white varnish round the top of the cell, 

 and on this lay the thin glass cover. After allowing 

 time for the varnish to dry, run two or more rings 

 round, and neatly, as a finish, one of green in the 

 centre of the white varnish. The slide having been 

 duly labelled is then fit to place in your cabinet. No- 

 thing is easier than this method, yet, like everything 

 else, the novice may fail in his attempts to succeed, 

 and after mounting a specimen iridium in the way 

 above described, he will perhaps in a day or two be 

 surprised to find he is unable to distinctly see his 

 object through a dimness which appears to have come 

 over the thin glass. This is caused by the object not 

 having been properly dried. Great care should be 

 taken that all specimens are thoroughly dried before 

 mounting. 



We now turn to the method of mounting in fluid, 

 which is by no means so easy or so certain of pro- 

 ducing good results. The apparatus and fluid required 

 may be briefly named as follows : — 



1. Ground-edge slips. 



2. Thin circles. 



3. Fine knife. 



4. Spirit-lamp. 



5. Glycerine jelly (the best). 



6. Gold size. 



7. White-lead varnish and brushes. 



In this case we will take as our example for mount- 

 ing a specimen of Aregma bulbosum, of the order 

 Puccinia. Having seen that your slide is well 

 cleaned, take the leaf with the A. bulbosum on it, 

 and with the fine knife scrape on to the slide sufficient 

 spores to fill the field of view without crowding it. 

 Next take up some glycerine (which has been placed 

 in a cup of very hot water in order to liquefy) in a dip- 

 ping-tube, and gently let fall one drop on to the spores, 

 then hold the slide over the spirit-lamp in order that 

 all shall be warm, then very gently place the thin 

 glass cover over the medium, and put the slide aside 

 till cold. When the glycerine has well set, take a 

 knife with slightly warmed blade and scrape all the 

 superfluous glycerine from the outside of the thin 

 glass cover ; next run three rings of gold size round, 

 allowing each to thoroughly dry before the next is laid 

 on ; after this has been done, finish with white and 

 green varnish as in dry mounting. In this method 

 the difficulty will be how to obviate air bubbles ; these 

 in working with glycerine are its great drawback. I 



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