383 
Cramer has observed the growth of cell walls of certain Si- 
phonacez when separated from the living cytoplasm. Numerous 
other Observations have been made to demonstrate that the cell 
wall of many plants is built up of living plasomen capable of con- 
siderable growth. Pfeffer and others are therefore far from right 
when they term the cell wall a dead substance. 
The question whether cytoplasm, or to use a more correct ex- 
pression, plasomen can be induced to divide outside of the living 
cell may be settled before very long. I believe it to be only a 
question of environment, and not a question of germ-plasm, as 
Wiesner and others seem to think. 
UNIVERSITY OF ILLINOIS, CHAMPAIGN, ILL. 
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