16 Cultivation of Microscopic Fungi. 1 'liTunlJi/xurffi"' 



The medium should not touch the inner edges of the tin-foil at 

 any part. 



To procure a satisfactory moist chamber occupying but Httle 

 space, the sHdes were set in small porous battery cells, previously 

 thoroughly cleansed and moistened with freshly-boiled water, and 

 set in a basin of the same to the depth of half an inch, the basin, 

 with levelled edges, being covered by a plate of clean glass. Those 

 shdes intended for diffused light were placed in cleaned damp white 

 porous cells set in water as the others, and covered with glass, the 

 face or cover side of the slide leaning towards the inner surface of 

 the battery-cell ; a small cell would thus hold four slides occupying 

 little space. The external temperature, if not sufficiently high, 

 must be raised artificially by a water-bath, or the basin set in a 

 warm place. 



The slides when removed are bedewed with moisture ; but if 

 rested on end, in a clean tumbler (warm if necessary), and covered 

 with a bell-glass, this soon disappears, and permits examination with 

 any power up to a ^th. 



Although the slide and cover were generally fogged with mois- 

 ture, I sometimes found the droplet had considerably diminished, 

 and the slide presented surfacas barely moist, especially if cover and 

 slide had not been most carefully cleaned. To meet this difficulty, 

 which was somewhat serious, especially if the slide had to be 

 watched many days, it occurred to me that if an artificial cultivating 

 fluid was made, which would be hygrometric, besides containing the 

 elements of nourishment considered useful for the colour and growth 

 of the fungi, much of this difficulty might be overcome ; hence, after 

 several trials, the following was selected and successfully used : — 



Dextrine, 2 grains ; phosphate soda and ammonia, 2 grains ; 

 saturated solution of acetate potash, 12 drops; grape sugar, 16 

 grains ; freshly-distilled water, 1 ounce ; boiled in a clean glass vessel 

 (thin beaker or large test-tube) for 15 minutes, covered whilst boiling 

 and cooling ;■ when settled poured into perfectly clean two-drachm 

 stoppered bottles, and set aside for use. Sometimes with the culti- 

 vating fluid other media were added on the sHde. 



To preserve some of the perfect forms of fungi found on plants, 

 or produced by > cultivation, &c., a saturated solution of acetate of 

 potash was employed with success. There is, however, a little diffi- 

 culty often from the repellent nature of the heads when beset with 

 spores, and retaining air in their interstices, in using this medium 

 for mounting ; but flooding the specimen momentarily with alcohol 

 diluted to the point when it readily touches or wets all the surfaces, 

 and draining it from the slide before applying the mounting solution, 

 readily overcomes this little trouble, and with scarcely any appre- 

 ciable change in the appearance of the spores or mycelium ; at least 

 such is my experience. I prefer it to glycerine or any other solution 



