THE FOOD OF THE PLANT 



19 



monocotyledon [e.g. Indian corn, palm). These should 

 stand in some coloured liquid, such as red ink or a 

 solution of eosin, until the leaves are turning red. 

 At this point the stems should be cut transversely and 

 longitudinally. 



Observations. — The parts of the stem which become 

 red are shown in the following table (Fig. 6) : 



When similar branches which have not been in red 

 ink are examined,' the same differentiation of parts 

 can clearly be distinguished even in the uncoloured 

 stem. 



If the various parts are pricked with a needle, the 

 red-staining portions will usually be found to be the 

 hardest. 



Inferences. — The red ink, or, more generally, the 

 solution from the soil, passes up the stem through the 

 hard part only. This part is the wood : it is arranged 

 either in a complete cylinder or in isolated strands 

 which may be regularly or irregularly disposed. 



The Structure of the Stem of the Plant.— It will be 



