The action of varying concentrations of CO2 in light and in darkness on P.claviforme and P.isariaeforme was studied.In the former, the shape of coremia Air Purifiers was influenced but dry weight was not.In P.
isariaeforme increase of concentrations of CO2 inhibits development of coremia, and in light, results in excess of dry Wallplate Mounting Clip weight.Experiments applying C14O2 revealed that both may assimilate carbon from the air.