[Vor. 4, 1917] 
ANNALS OF THE MISSOURI BOTANICAL GARDEN 
EXPLANATION OF PLATE 
PLATE 18 
All figures are reproduced from camera drawings Х 580. 
ір. 1. Typical cell with chloroplast only partially lining the 
all. 
Figs. 2-5. Various examples of irregularities in thickened wall. 
Fig. 6. Internal thickening of wall penetrating cel 
Figs. 7-11. Successive stages in the formation of spores. 
Figs, 12-13. Means of spore liberatio 
Fig. 14. Calcium oxalate crystals eras in cell. 
