46 ELEMENTS OF BOTANY 
Chip away part of the shell from the larger end of the egg, place 
it in a wide-mouthed bottle or a small beaker full of water, as shown 
in Fig. 21, then very cautiously pierce a hole through the upper end 
of the eggshell by pushing a knitting-needle or 
wire down through the glass tube. 
Watch the apparatus for some hours and note 
any change in the contents of the tube. Explain. 
The rise of liquid in the tube is evidently due 
to water making its way through the thin mem- 
brane which lines the eggshell, although this mem- 
brane contains no pores visible even under the 
microscope. 
Fic. 22. 
aA, a very young root-hair; B,a 
much older one (both greatly 
magnified). e, cells of the epi- 
dermis of the root; n, nucleus: 
Fic. 21. Egg on Beaker of Water, Ss, watery cell-sap; p, thicker 
to show Osmosis. protoplasm lining the cell-wall. 
60. Osmosis in Root-Hairs. — The soil-water (practically 
identical with ordinary spring or well water) is separated 
from the more or less sugary or mucilaginous sap inside 
of the root-hairs only by their delicate cell-walls lined 
