NUTRITION 15 
be found and that will help us to see them length- 
ways. In order to do this we must slit the root 
in half down the middle, and then take a section off 
the slit surface and put it on to the slip in a drop or 
two of spirit and cover it as before. If we have had 
good luck we shall then be able to make out the mean- 
ing of the illustration. (See Fig. 3, Plate I., p. 10.) 
We can proceed in the same way with the stem and 
the leaves and so trace the pipes right into the latter ; 
they are to be found in the veins of the leaves, and, of 
course, the thickest veins are the easiest to deal with. 
We must pass over what happens to the food ingredi- 
ents inside the leaves, except to say that a leaf is not 
green in the same way that a dress or a piece of blot- 
ting paper is green—that is to say, it is not green 
through and through. We may have noticed, when 
we stripped the piece of skin off the snowdrop’s leaf, 
that it was not green, at any rate so far as we could 
judge, and if we cut the leaf across or lengthways 
we shall perhaps be surprised by the comparatively 
little evidence of green that we can find in the bulk 
of it. 
The fact is that the green consists, not of any 
continuous layer or layers, but is distributed as small 
specks in ‘the life-substance. It is really a liquid which 
saturates the specks, and it is in these green “ corpus- 
cles”? as they are called that the food ingredients 
are forged by the sunlight into food. 
One of the commonest forms that the food takes, 
and the one that is the easiest to see, is starch, and 
most people are aware of the fact that starch enters 
very largely into our own food, such as potatoes and 
rice ; so we find that vegetable flesh derives nourish- 
ment from the selfsame foodstuff as our own flesh, and 
Cc 
