222, VEGETABLE PHYSIOLOGY 
stores of proteins found in seeds, which have been found 
to give rise to similar amino-acids before being transported 
from the site of storage. To this point we shall return in 
a subsequent chapter. 
We cannot say either in what form proteins are tem- 
porarily stored in the cells of their first formation. Pro- 
bably, like starch, they are made indiffusible and so retained 
in the cell. But whether they are thrown into a solid 
form we do not know. If so, they are amorphous and are 
hidden away in the substance of the protoplasm. They may 
be kept in solution in the sap which saturates it. Different 
kinds of globulin and albumin have been found in the 
cells in different regions. It is possible again that the 
manufacture of protein may be only so great as to provide 
for the needs of the cells in which such formation takes 
place, together with the amount that can diffuse during 
such manufacture, so that there may be no occasion for a 
temporary storage there. We are not sure whether the 
process of their formation is a continuous one, or is inhibited 
at night. 
The translocation of food has no very determinate 
direction. On leaving the cells which are the seats of its 
formation, its path ig dependent on physical processes 
taking place in different parts of the plant. We can study 
it most simply by taking a special case, which as before 
may conveniently be that of sugar. We are not familiar 
with the physical process of its passage from cell to cell: 
it is unlikely that osmosis causes it to pass so regularly, and 
diffusion is apparently not sufficiently rapid to explain it : 
possibly it may be picked out from the cell-sap by the proto- 
plasm and passed on to the vacuole of the next cell and 
so forward by a kind of secretion. We know, however, 
that it is conducted through the parenchyma to the 
fibro-vascular bundles, the bast of which, we have seen, 
forms its principal path. These extend in complete con- 
tinuity throughout the plant, so that any travelling com- 
pound can be transported from the leaves to the growing 
