55° BOTANICAL GAZETTE [JUNE 
The differences in the growth in the levulose and glucose solu- 
tions are of considerable interest. Brown and Morris (1), working 
with Tropaeolum majus, believe that glucose is more quickly used 
up for respiration and possibly also for tissue forming than is 
levulose. Linpet (4), working with the yeast and fungi, concluded 
that glucose is mainly concerned in respiration, while levulose is 
more particularly concerned in the elaboration of tissue. In the 
case of Ceratodon purpureus the elaboration of tissue is certainly 
far greater with levulose than with glucose. The data, although 
not conclusive, also suggest that the elaboration of tissue in the 
presence of levulose is more economical than in the presence of 
glucose, as the sugar used per unit of dry matter formed is generally 
smaller in the levulose than in the glucose solution. 
Summary 
1. Under the conditions of the experiments reported organic 
carbon in the form of levulose, glucose, galactose, lactose, cane sugar, 
and maltose is absorbed and utilized by Ceratodon pur pureus. 
2. Starch is formed in the dark from levulose, glucose, galactose, 
lactose, cane sugar, and maltose. 
3. Mannite, glycerine, and starch cannot be utilized by this 
moss. 
4. The amount of growth with levulose as the source of carbon 
is 2-7 times greater than that with glucose as the source of carbon. 
5. In the presence of levulose the greater amount of growth 
occurs in the dark. With glucose the greater amount of growth 
occurs in the light. 
6. Light seems to be necessary for the formation of moss plants, 
even though available carbohydrate is furnished. 
ALABAMA POLYTECHNIC INSTITUTE 
AUBURN, ALA 
LITERATURE CITED 
1. Brown, H. T., and Morris, G. H., A contribution to the chemistry and 
physiology of foliage leaves. Jour. Chem. Soc. Trans. 63:604-677. 1893- 
2. Dox, A. W., The intracellular enzymes of Penicillium and Aspergillus with 
special reference to those of Penicillium camembertii. U.S. Dept. Agric., 
Bur. An. Ind. Bull. 120. pp. 70. 1910. 
