THE ROOT 59 
to pull them down against the opposite pull of the 
water in the earth. 
| When however gravity and water pull in the same 
direction the root travels downwards. Fill a tumbler 
about a quarter full of water, and tie over the top 
HYDROTROPISM 
2% 
272+: 
te” rf 
Z 9 
z 5° 
a 
‘ s° 
. Cy, « 
aty*) 
i ‘ 
. 
= i, 
| 
MOIST SOIL 
ROOTS-CURVING- BACK 
FOR-WATER 
ROOTS -TRAVELLING 
THROUGH: MOIST-AIR 
TOWARDS-WET: POT 
a piece of butter muslin, allowing it to sag in the 
middle. On the muslin, in damp sawdust, place germi- 
nating beans, allowing the radicle to protrude through 
the muslin into the glass. Cover the glass with a cloth 
and keep the sawdust moist. The roots will not change 
their direction, but will continue to travel downwards 
