142 
B. Muriel Bristol. 
develop the very numerous chloroplasts characteristic of the lower 
cells of a well-grown protonema. 
Fig. 3. Cells from resting filament. A, cell filled with globules of oil ; 
B, cell with enormously thickened walls and a few small oil globules, a, oil 
globules, x 428 diameters. 
A subsequent examination of some of the dry soil from which 
the cultures had been made, and also of fresh samples obtained 
from the Rothamsted Laboratory for the purpose, which had been 
soaked out with water for a few hours, revealed the presence of the 
resting protonema in the soil itself, and proved without the slightest 
possibility of doubt that the presence of moss protonema in the 
cultures was not the result of a foreign infection. The cells of the 
resting filaments observed in the dry soils were all completely filled 
with oil, having the appearance of the cell at d in Fig. 2, B ; this 
indicates that the two kinds of cells described above only represent 
different stages of development, and that probably all the cells were 
originally completely filled with oil. 
