100 APPENDIX. 



In collecting Infusoria, several clear phials, with 

 wide mouths, and cork stoppers, are necessary; and 

 a good pocket magnifier, with three lenses of dif- 

 ferent powers, will be required, to examine objects on 

 the spot, that useless or uninteresting specimens may 

 be rejected. The phials should be filled with fresh 

 water nearly to the top; and small portions of the 

 aquatic plants, to which animalcules are attached, should 

 be collected ; but the phials must not be crowded with 

 leaves or stems. The corks must be removed as soon 

 as possible, for if the air is long excluded, many of the 

 animalcules will perish. In winter, Infusoria may often 

 be found around the Confervas under the frozen water. 

 In searching for animalcules in a muddy pond, it is advi- 

 sable that some of the water should be poured through 

 a piece of linen, or silk, to get rid of the extraneous 

 matter; for the Infusoria will pass through the filter, 

 and thus be more easily detected. 



To procure the Infusoria from vegetable infusions, it 

 is only necessary to put fruit, hay, grass, or other 

 vegetable matter, into water, and expose it in open 

 vessels for a few days : a pellicle or film of mucus will 

 soon appear on the surface, and be found to consist al- 

 most entirely of animalcules. 



To select specimens for examination, a small quantity 

 of water from one of the phials should be poured into a 



