546 BOTANICAL GAZETTE [JUNE 
and is described by REED (5). The carbon compounds were all 
Merck’s products. Dextrose, pure, ‘“‘Mulford’’ and Schering’s 
levulose were also used in repeating some of the experiments. 
Sufficient of the organic compound was added to make a con- 
centration of o.1 mol. The culture vessels were 125 cc. Erlen- 
meyer flasks, containing 50 cc. of solution. Those sugars, such as 
cane sugar, which could be hydrolyzed were sterilized in an Arnold 
sterilizer and tested for hydrolysis before use. After sterilization 
a reek 
Fic. 3.—Ceratodon purpureus grown in nutrient solution in light for 2.5 months: 
on left grown without organic compound; on right grown in 0.1 mol. maltose 
the flasks were inoculated, as previously described, with the moss 
protonema. The moss was grown for 2.5 months in the presence 
of each carbon source in triplicate culture both in the light and in 
the dark. 
In the dark the moss grew in the levulose, glucose, cane sugar, 
maltose, galactose, and lactose solutions. The amount of growth 
was greatest with levulose as the source of carbon. In the galactose 
and lactose solutions the growth was very slight. No growth, 
save a slight lengthening of the filaments of the original material, 
occurred in the check, nor in the presence of mannite, glycerine, or 
starch. In all cases in the dark the growth consisted of protonema. 
No moss plants were produced. The protonema, instead of having 
