1908] POND—LATERAL ROOTS 413 
made, therefore, from freehand sections mounted in pure lactic acid 
mixed with iodin. In order to have the sections clear and free from 
air, they were exhausted under the air pump. Only Vicia Faba and 
Lupinus albus were studied. Radial sections of the radicle showing 
the lateral root in median view are the best. 
The cells of the cortex are not compressed to the stage of collapse 
until the lateral root has advanced about one-half the distance toward 
the epidermis. In earlier stages, when the lateral root has advanced 
only two-fifths the distance toward the cuticle, one may still find all 
the cells of the cortex uncollapsed and in natural cell connection, 
though of course displaced and compressed. The lateral root, there- 
fore, has made a very difficult part of its journey without the slightest 
possibility of any digestion of the cortical cells. In the lupin the 
cells of the cortex have too little starch to note any possible autolysis, 
but in Vicia there is plenty of starch, and one can easily see that there 
is no difference in the starch content of the cells immediately sur- 
rounding the lateral root in comparison with those of other regions 
of the cortex. The same is true when the lateral root has advanced 
to the epidermis. Even in the cells which have been compressed 
to collapse, and in which the protoplasm looks wasted, the starch 
seems to be present in undiminished quantity. When the lateral 
Toot has advanced about one-half the distance toward the cuticle, 
the cell connection of the cells just outside the apex of the lateral 
Toot is broken in that region, and the cortical cells are thus pushed 
aside by the lateral root as is water by a boat. Those cells though 
now collapsed may remain undigested and be carried by the lateral 
nO outside the epidermis. I have found, though very rarely, cases 
in which the cell connection of the displaced cortical cells was com- 
Plete along the side of the lateral root, even at the time of the arrival 
of the latter at the epidermis. Any digestion of such cells is there- 
fore excluded. Usually the cortical cells are so dislocated and so 
isarranged that the cell connection cannot be established. However, 
a few cases only are necessary to show that there can be no digestive 
action on the part of the lateral root either upon the cells of the cortex 
or of their contents. 
Of course there must be some resorption of substance, and whether 
this is done by the cortex or by the lateral root I cannot say. As the 
