414 BOTANICAL GAZETTE [DECEMBER 
cortical cells collapse, the protoplasm of course loses its turgor and 
further compression drives the cell sap from the cell. Since the 
osmotic pressure of the lateral root is much higher than that of the 
cortical cells, there is probably some adjustment in the matter of 
resorption. Some of the solutes may go into the cortex and others 
into the lateral root. The apical cells of the lateral root are abun- 
dantly filled with starch, much more so than those of the cortex. 
Turgor estimations 
If the young lateral root mechanically pushes its way through the 
cortex, one would expect to find that the turgor of the cortical cells 
is less than that of the cells of the advancing lateral root. Longitu- 
dinal sections of the main root showing the lateral root in median 
view were immersed in various concentrations of potassium nitrate 
and of ammonium chlorid. After being exhausted under the air 
pump for thirty minutes, the degree of plasmolysis was determined. 
Essentially the same figures were obtained for Vicia Faba and for 
Lupinus albus. The figures given hold for sections in which the 
lateral root has nearly emerged. In 2 per cent. KNO, no plasmolysis 
could be observed in any of the tissues; in 3 per cent. KNO, there 
was initial plasmolysis of the cortical cells only. The turgor of the 
cells of the central cylinder and of those of the endodermis undisturbed 
by a lateral root seems to be a little higher than that of the cortical 
cells. In 4 per cent. KNO ; the cortical cells are strongly plasmolysed, 
the endodermal cells covering the apex of the lateral root are not at 
all plasmolysed, the cells of the central cylinder and those of the 
undisturbed endodermis are somewhat though not strongly plasmo- 
lysed. In 5 per cent. KN O, there is total plasmolysis of all the cells 
except those of the lateral root itself and of the endodermal cells 
covering the apex of the lateral root. Some cells at the base of the 
lateral root show plasmolysis in 5 per cent. KNO,. In © pet - 
KNO, the endodermal cells covering the apex of the lateral root 
show initial plasmolysis. The maximum turgor for the endoderm's 
is found in those cells which cover the apex of the young lateral r00t- 
From the apical cells toward the base of the lateral root the turgor 
of the endodermal cells seems to gradually decline, until only a short 
distance in longitudinal direction of the main root from the raat 
