THE FOOD OF PLANTS 125 
other, we may begin the consideration of them in detail 
with an inguiry into the preliminary absorption of the 
materials from which the food is ultimately made. Even 
here we meet with some complexity, as the ordinary green 
plant shows marked differences in behaviour from its 
parasitic relative and from the great class of Fungi, which 
possess no chlorophyll. We have already pointed out that 
the construction of food does not follow exactly the same 
course in green plants and saprophytic fungi, the chief 
point of difference being seen in connection with the 
carbohydrates. It will be best to consider first the 
ordinary terrestrial green plant, noticing in passing 
differences in behaviour shown by aquatic and epiphytic 
forms. 
