ve A AMERICAN MIDLAND NATURALIST. 
and they always get by themselves sooner or later, after de- 
vouring all traces of plants. 
s to the method of treatment that appears to be benefi- 
cial in developing microscopic plants in the laboratory, we 
may say in general, that it consists essentially in a process of 
domestication. This is as true of plants as of animals. All 
velop as in their natural home, or as near as possible to the 
conditions in which the captives can be coaxed to accommo- 
nearby in the field, places where desirable specimens are wont 
to develop. By going to such places one can in a few days 
or weeks obtain excellent laboratory material out of season 
*The American Midland Naturalist, Oct., 1909, Vol. I, pp. 82-87. 
