98 THE NATURE-STUDY OF PLANTS 
During its life it is busy making food, which is 
stored up in the stem and the stump against the time 
when it will be required to nourish the flowers and the 
seeds which will be produced later on. 
The last thing that happens before its dissolution 
is that all the food that it still contains passes out of it 
and into those parts, including the stump, that are not 
going to die yet awhile (see Fig. 34): the plant 
must not and does not waste the precious stores that 
have been formed in its life-substance by the green 
leaves and the light of the sun. 
It has been suggested that when the Herb Robert 
grows on the side of a wall, as it sometimes does, these 
stumps help to support it and to relieve the strain 
upon the roots caused by the weight of the plant. 
I dare say the lower ones act in this way, and indeed 
I have no doubt that they must do so whenever they 
happen to catch in a crevice or a small hole, but since 
they are found regularly and in equal abundance upon 
plants growing upon flat ground where no such support 
could be of any use, we must not think of them as being 
produced for this reason: their true function is to 
act as a food reservoir, or as we should say in our own 
case as a larder or a store cupboard. 
I must now draw attention to a point of interest 
in the blade of the leaf. It is cut up into somewhat 
small areas, and this feature of leaf areas of small 
extent is commonly found in plants that are annuals 
and grow under conditions similar to those of the 
Herb Robert. 
A large low-growing undivided leaf would be likely 
to have a considerable portion of its surface shaded 
or overgrown by the surrounding herbage, involving 
a considerable amount of waste of material, hence we 
