194 MISSOURI BOTANICAL GARDEN. 
The generators were so regulated that the gas came off in 
a moderately slow stream of bubbles and continued long 
enough to insure complete saturation. The end flask con- 
tained nothing but water and served to prevent the entrance 
of air or atmospheric gases. 
November 14, the following were used and placed in the 
order named: Llodea, Pithophora, Cladophora, Spirogyra 
and Anabaena. 
November 21, Elodea in oxygen seemed to be dead, while 
that in the COz seemed brighter than the check. All were 
renewed and continued as before. 
November 26, Cladophora in COz was dead and disin- 
tegrated. 
Cladophora in O2 was much like check; others unchanged. 
The above results gave little promise of any conclusions 
further than to indicate the possibility of continuing an 
experiment on this plan and that different plants showed 
a difference in response and endurance. But other factors 
would likely enter into such treatment, as light, temperature 
and dissolved salts. 
December 7, new material was arranged and continued to 
December 24, when the conditions were as follows :— 
Condition Large Small Stigeoclo- / 
Dec. 24 tideotiniebe Hydrodictyon | Cladophora nium Pithophora | Elodea 
Check Bright Spoiled Unchanged Dead Green Dead 
In CO2 Fair Eangpoved re ts - green 
In O2..... Good Basie { oar 
A large amount of Hlodea was kept in jars in various con- 
ditions as to light, etc., and it all did well, so the material 
was not at fault. Stigeoclonium did not do well under any 
conditions. 
Not much change occurred in any of the cultures, except 
that Clathrocystis (from which important results were ex- 
pected) soon died in all the series as it had done under various 
kinds of treatment throughout the summer. One large 
jar, after the excessively hot weather was over, kept in 
