The Preparation and Use in Class Demon- 
stration of Certain Cryptogamic Plant 
Material. 
BY MARSHALL A. BARBER. 
The following is a description of some methods in use in the 
laboratory of Cryptogamic Botany in the University of Kansas. 
Some of these, in various forms, perhaps, may be now in use by 
many teachers; but they are described in the hope that they may 
be in part new, if not to all, at least to some who are engaged in 
teaching Cryptogamic Botany. 
For demonstrating the evolution of oxygen by Algae, and the 
relation of Bacteria and Infusoria to this gas, the following appa- 
ratus is used: A drop of water, or nutrient substance, containing 
the Alge, Bacteria and Infusoria is placed in the center of a large 
cover glass. A smaller cover is then placed over the drop and the 
whole sealed, smaller cover down, to a ring cemented to a slip or 
any of the devices ordinarially used in making hanging drop cult- 
ures. There should be just liquid enough to fill the space between 
the covers, and the smaller cover should, of course, be less in 
diameter than the ring, so that a dry area will separate the liquid 
under the cover from the cement. The preparation is thus enclosed 
ina moist cell, and may be studied for days. Observations may 
be made with lights of different colors, different gases may be in- 
troduced into the cell, and the changes in the organisms due to 
these factors or to variations in their nutrient medium may be 
readily noted. 
In obtaining plasmodia for the study of Myxomycetes during the 
winter months I have had very good success with sclerotia. Scle- 
rotia of one or two forms are rather abundant in this region, and 
are usually found in rotten wood or on the ground under old logs. 
Pieces of this material put in a moist, warm place usually develop 
plasmodia in a few hours; and the plasmodia may be nourished and 
made to fruit or allowed to return to the resting form. I have used 
rotten wood and fleshy fungi for feeding plasmodia. Small plas- 
(111) KAN. UNIV. QUAR., VOL. VII. NO. 2, APR. 1898, SERIES A, 
