^ml^i.'jLn.Tis'a'] Cultivation of Microscopic Fungi. 15 



over, being too imjjerfect for publication, and others only slightly 

 sketched. 



As the subject is likely to occupy considerable attention at home 

 and abroad, and different observers employ different plans, I venture 

 to shortly notice the method adopted by myself, which proved 

 useful and inexpensive, and allude more particularly to that em- 

 ployed by Drs. Billings and Curtis, as stated in their portion of the 

 late " Eeport on the Cattle Plague in America." 



The great difficulty, if not almost absolute impossibility, of con- 

 ducting any series of experiments, which, however free to legitimate 

 deduction, shall not be open to useless controversy, determined me 

 to use only such means as might be called simply precautionary, of 

 easy arrangement and manipulation, one object being to determine 

 some useful form of cultivating-slide with the ordinary 3-inch 

 microscopic object-slide. Several plans were tried, but the one now 

 described selected. It was made as follows, to be used with thin 

 fths of an inch square covering-glass, such as is usually employed 

 for a yVth-objective. 



A piece of tin-foil, of the stoutness of ordinary note-paper, was 

 cut into squares of one inch diameter, a portion was then removed 

 from a square by cutting it from one side almost to the opposite, 

 then at right angles and again at right angles, thus leaving a 

 strip of the shape of the letter LJ "^i^^i ^ ^^^ ^^se, and limbs 

 of equal length and width ; from the j)iece removed a narrow slip 

 was cut from three sides, and then a portion removed from it, as in 

 the first piece, thus forming a smaller letter U ; the largest was 

 cemented to the surface of a well-cleaned slide with easily-melting 

 marine glue, or Bell's cement thickened with gum-shellac; the 

 smaller one was then similarly fixed within the larger one, the limbs 

 being turned to opposite sides of the slide, as seen in the figure, 

 thus afibrding a central space for the material under examination 

 and a narrow channel each side for the admission of air. 



The fungi or spores selected were placed on the cover, under the 

 dissecting or erecting microscope, with a droplet of the medium to 

 be employed or cultivating solution. This was examined under the 

 microscope with a power of 150 or 200 diameters, and if satisfactory, 

 placed at once over the central space of the slide (which, after 

 cleaning with liquor potassae water and alcohol, if cemented with 

 marine glue, or diluted alcohol if with Bell's cement, was kept 

 turned upside down, one edge resting on a j)iece of glass until 

 wanted), and the edges of the thin cover resting on the slip of tin- 

 foil, were then closed up with wax softened by oil or with Bell's thin 

 cement, except at the spots corresponding to the two narrow pas- 

 sages marked * * in the figure. If thought necessary, a duplicate 

 slide was similarly prepared, one being left in diffused light, the 

 other in darkness in the moist chamber. 



