Chap. I.] BY THE SURFACE OF THE ROOTS. 
23 
and of the root downward; and the seedling is 
entirely dependent on the seed for its life and for 
its growth till the roots have become woody. 
Still farther to prove this, I have placed horse- 
chestnut seedlings raised in water, having roots 
about three inches long, with the tips and lower 
parts of the roots in a shallow saucer of water, and 
with the seeds and plants outside the saucer. All 
died and dried instantly. These, then, while alive, 
were supplied by absorption from the surface of 
the seed, and were not indebted to the immature 
roots, with their spongioles and capillary stomata. 
And where are the spongioles and capillary sto¬ 
mata which supply the surface of the seed ? 
One of these experimental plants lived for Symmetrica! 
growth on root 
nearly ten years in water, and was then only of horse-chest-' 
killed accidentally. The first side-fibres or 
shoots which are developed on the roots of 
horse-chestnuts grown in water are regularly 
arranged in six vertical lines along the root. 
This is the only approach to symmetrical 
growth that I have ever remarked on the root of 
a tree. The side-fibres of the root come from 
the woody part of the main root, as branches do 
from the woody part of the stem ; and I imagine 
that, when side-fibres are first developed on the 
main root, this main root is first becoming suffi- 
