86 THE AMERICAN MONTHLY [April, 



ing the bottle is I'emoved. This, taking the place of the ring, can be 

 thrust under the water and the coveted plant reached and brought to 

 the surface. 



Avoid the necessity of carrying home a useless burden of w^eed. For 

 this purpose there are various home-made appliances in the shape of 

 square and round clear glass bottles, but the handiest, as also the most 

 efficient of these appliances, may be constructed thus : Take two pieces of 

 clear patent plate glass, about three and a half inches square, grind their 

 edges, and cement with marine glue between them, at the side and bot- 

 tom, some slips of stout plate glass. This forms a strong shallow form 

 of trough, in which aquatic plants may be placed for examination by 

 the pocket lens. The pai-allel sides of the glass trough favor the exami- 

 nation. Portions of the plant may be selected for further inspection, 

 and placed in separate tubes. It is not a good plan to huddle every- 

 thing collected into one stock bottle. Remember that overrcrowding 

 in any shape is not only detrimental to animal existence, but even fatal. 

 In addition to the collecting-stick, bottle, ring, and hook, a muslin ring- 

 net and a shallow spoon as recommended in diatom and desmid collect- 

 ing should be added. Arriving home from a hunt the material will 

 need further examination, distribution into separate glass tanks, and 

 placing in the light of a north window, the direct rays of the sun being 

 prejudicial by over-heating a small quantity of water, and by favoring 

 the inordinate growth of confervse. Many collectors and breeders of 

 infusoria seem to consider the pleasant summer afternoon the only and 

 proper times for these collections. No greater mistake can be made, 

 for though they may be rewarded by the capture of forms of great 

 beauty by confining their operations to this one season of the year, they 

 leave uncaptured many forms in their early and transitional stages. 

 Visit those same ponds in the winter, and beneath the snow and ice is 

 an abundant harvest of material. You can develop the ova of many of the 

 fresh-water fauna. For this purpose a slide, capable of being trans- 

 ferred to the stage of the microscope at any time without disturbing the 

 object under observation, must be added to the stock. of accessory ap- 

 paratus. Such a slide is known as a growing slide^ and many forms 

 have been devised. 



It often happens that in examining a gathering an organism is met 

 with about which the observer would desire to know more ; but to 

 transfer it from his slide to one of the growing slides in ordinary use 

 would most probably result in its loss or destruction. The slide now 

 about to be described is designed to supercede the use of the glass slip 

 generally used for this purpose, so that should such an organism pre- 

 sent itself it is not necessary to disturb it, but simply to insert an inlet 

 and an outlet thread of darning cotton in the openings at the sides of 

 the cell, attaching the inlet thread to a small reservoir of water a few 

 inches above the microscope stage, when a continuous current favored 

 by the capillary attraction of the cotton threads is made to pass through 

 the cell. Any number of these slides may be constructed by the mi- 

 croscopist himself, for by having half a dozen or so at hand it becomes 

 an easy matter to put any one having an object of interest on it aside 

 for future examination. They are designed with a view of being put 

 away in the gi^ooves of a slide box. Plain directions may here be 

 given for making them. The slide consists of the usual glass slip (3 



