16 THE CHICAGO ACADEMY OF SCIENCES 



If the specimen was mature, an abundant deposit of spores will 

 usually be found upon the slip and paper after the lapse of a few 

 hours. Their color in mass upon the paper should be noted, 

 and their size, shape and any peculiarities determined by exam- 

 ination with the microscope. 



Where frequent spore examinations are to be made, it is con- 

 venient to have a stand fitted with an eye-piece micrometer and 

 lenses giving a magnification of 400 diameters, this being the 

 standard in the published figures of these plants. With such an 

 outfit, it is only necessary to place a small drop of water on a 

 cover-glass, drop the cover carefully upon some portion of the 

 slip where the spores are rather thinly distributed, place the slip 

 upon the stage and focus. With such an outfit the spores of a 

 large number of specimens can be examined in a comparatively 

 short. time.. A record of the size and shape of the spores should 

 be written n the field-label. If the microscope is not fitted with 

 a micrometer, drawings of the magnified spores should be made. 



Spores of Polyporei, Boleti and the Hydnaceae may be ob- 

 tained by laying the plant, pore-surf ace downward, upon the glass 

 slip and paper; those of Clavariae and Thelephorae by laying- 

 one or more plants upon the slip and paper and covering with a 

 tumbler or bell-glass to exclude air-currents. When, after trial, 

 it is found impossible to obtain a deposit of spores, a section of 

 the pore-bearing surface can be examined under the microscope. 

 Measurements obtained in this way should be recorded as tentative 

 only, for the reason that the spores thus -seen are of various stages 

 of growth, and it is difficult to determine the average size or even 

 the typical shape and markings of those which are fully matured. 



DRYING AND PRESERVING. Woody plants and the small 

 agarics can usually be dried by placing them in a dry, sunny 

 window. The fleshy agarics, however, must be dried by artificial 

 heat and as quickly as possible. In the summer time, the kitchen 

 range is usually the best place. If this is not available, the plants 

 may be placed upon ordinary botanical wire presses or any con- 

 venient screen of wire netting and suspended over a gas burner or 

 kerosene lamp, keeping the specimens as near the flame as can be 

 done without scorching. After the plants are thoroughly dry 

 they may be kept in open boxes in any convenient dry place, 

 preferably one exposed to sunshine, until the end of the collecting 

 season. 



Freshly gathered plants may be preserved in jars or bottles 

 with a 2% aqueous solution of formaldehyde, or in methyl 

 spirit. If the former liquid is used the jars must be well sealed. 

 If after a time a cloudy deposit is seen at the bottom of the 

 jar, the formalin has evaporated to such an extent that it is no 

 longer preservative. In such cases the jars must be opened, the 

 liquid poured off and a fresh supply added. The temperature of 

 the room should not fall below zero C. If the plants are kept in 

 spirit this precaution is not necessary. 



It may as well be confessed that no satisfactory method of 



