The influence of mechanical resistance on the development 
and life-period of cells. 
FREDERICK C. NEWCOMBE. 
(Concluded from p. 199.) 
The effect of external mechanical resistance on the duration of 
the life-period of cells. 
The fact that meristem in growing points, in the cambium 
and in zones of plants that increase by intercalary growth, 
May preserve its functional capability for many weeks while 
suM casts has already been shown. From what is now to fol- 
low it will appear that the life-period of cells may be prolonged 
if their growth or that of neighboring cells is mechanically re- 
Strained. : 
After young aerial shoots of Juncus effusus had been, with- 
out detaching them from the rhizome, kept in gypsum casts 
at any time in this stem. The greater thickness was not de- 
Pendent on a radial elongation of cells so much as on an in- 
by first the branching and then the death of these two inner- 
MOSt rows of living cells. As it was, the central cylinder of 
Cells that Were 
Crushed toget 
