1. Rubber in canal cells, nearby cortex and inner 



ray cells. Root 1 .2 mm. diam. 



2. Older root. More rubber in rays. 



3. Root 2 mm. diam. 



4. Parenchyma ray from fig. 2. 



5. Upper part of hypocotyl, same age as fig. 1 . 



6. Longitudinal section through old wood. 



7. Longitudinal section through mature leptome 



parenchyma, with a few parenchyma ray cells. 

 6. Leptome; elongated elements. 

 9. Companion cells and sieve tubes. No rubber 



in younger leptome on the left. 



