206 VEGETABLE PHYSIOLOGY 
in the stem of another nearly related one, and the two are 
closely bound together. The graft or scion comes into such 
close connection with the stem or stock that the food which 
is contained in the cells of the latter passes into the tissues 
of the graft, which thus receive their nourishment. After 
a longer or shorter time the two become so completely united 
that they live subsequently as a single organism, and the 
processes of carbohydrate and protein construction proceed 
as ina normal plant. 
