544 
The Ohio Naturalist. 
[Vol. XV, No. 8, 
Fig. 2. 
Fig. 2. Radial view of Picea canadensis, showing uniseriate medullary 
ray in section. 
r. t. ray tracheids. 
r. p. ray parenchyma, 
w. t. wood tracheid. 
e. w. r. t. end wall of ray tracheid, showing bordered pits in section, 
e. w. end wall of ray parenchyma cells with simple pits in section. 
s. p. s. simple pits in section. 
h. b. p. s. half bordered pits in section, 
b. p. w. t. bordered pit of wood tracheid. 
b. p. r. t. bordered pit of ray tracheid. 
s. b. p. semi-bordered pit of ray parenchyma. 
