CHAPTER III. THE ROOT 
I. OSMOSIS AND THE ACTION OF THE CELL 
Marteriau. — For experiments in osmosis provide fresh and boiled 
slices of red beet, a fresh egg, a piece of ox bladder or some parchment 
paper; glass tubing, thread, twine, elastic bands, salt and sugar solutions. 
A common medicine dropper with the small end cut off will answer instead 
of tubing for making an artificial cell; or an eggshell may be used, by 
blowing out the contents through a puncture in the small end, and care- 
fully chipping away a portion of the shell at the big end, leaving the lining 
membrane intact. The different liquids can be put into the shell and the 
exposed membrane placed in contact with the liquid 
in the glass, by fitting over the latter a piece of card- 
board with a hole in the center large enough for the 
exposed surface to protrude sufficiently to touch the 
water. 
55. Object of the experiments. — In or- 
der to understand clearly the action of roots 
in absorbing nutrients from the soil, it will 
be necessary to learn something about the 
movement of liquids through the cells, upon 
which the physiological processes of the 
plant depend. For this purpose make an 
artificial cell by tying a piece of ox bladder 
or parchment paper tightly over one end of 
a small glass tube, as shown in Fig. 71. 
EXPERIMENT 39. How DOES ABSORPTION TAKE 
PLACE IN THE CELL? — (a) Put some salt water in ——— 
a wineglass, partly fill the tube of the artificial cell F1c. 71.—Artificial 
with fresh water, and mark on the outside of both cell. 
vessels the height at which the contained liquid stands. Set the tube 
in the glass of salt water and wait for results, having first tested care- 
fully to make sure that there are no leaks in the membrane. After half 
an hour, notice whether there is any increase of water in the glass, as 
indicated by the mark. If so, where didit come from? Is there any loss 
53 
