No. 415.] THE STUDY OF INFUSORIA. 559 
washing away of any organisms once placed within its meshes. 
Far less time and care, consistent with the safety of the prepa- 
ration, are necessary than in the common method of making 
preparations “under the cover-glass" with the object lying 
free. At any stage in the process examination is convenient. 
The preparations can also be stored in the alcohols, etc., if 
desired. Owing to the use of dry cotton and the horizontal 
lowering of the cover-glass, the organisms are caught zw the 
meshes of the cotton, seldom under or over its fibres. .But few 
if any organisms need be lost, either in this procedure or sub- 
sequently. Success depends upon a proper adjustment to each 
other of the size and quantity of the materials used, and this 
can be accomplished after a few trials. 
CAMBRIDGE, May, 19o1. 
