1918] ROBBINS—ASSIMILATION OF CARBON 547 
the familiar yellow color of chlorotic higher plants, was a dark red- 
dish brown. 
By the use of iodine starch was demonstrated in the protonema 
grown in the levulose, glucose, cane sugar, maltose, galactose, and 
lactose solutions. The protonema grown in the levulose solution 
contained the most starch. At the end of the experiment it was 
found that the cane sugar was completely inverted. The use of 
Barfoed’s solution and the osazone test failed to demonstrate the 
Ley viose 
Dextrase 
Fic. 4.—Ceratodon purpureus grown in nutrient solution in light for 2.5 months: 
on left grown in 0.1 mol. dextrose; on right in o.1 mol. levulose. 
presence of glucose in the maltose solution. No glucose was found 
in the lactose solution. 
In the light there was growth in all the cultures, showing that 
none was toxic to the moss. The greatest amount of growth was 
found in the levulose solution. Moss plants developed in all 
cultures. To some extent the macroscopic appearance of the 
growth in the light seemed to be influenced by the particular sugar 
used. For example, in the glucose solution sharp clean cut moss 
plants were produced. In the levulose solution many moss plants 
were formed, but they were shorter and thicker. This difference 
in the moss plants and the excess of protonema in the levulose 
solution gave the culture as a whole a woolly appearance. The 
