Fig. 1. — Showing cross section of Carolina poplar (Pojfuliis deltoidea Marsh). 1, Cross 

 section of normal stem, enlarged; 2, same, showing abnormal growth; 3, naked-eye 

 view of same; 4, section of a normal stem; 5, cross section of trunli of tree showing 

 the splitting of the hark; a, bark; 6, cork cambium; c, cortex; rf, phloem; e, abnor- 

 mal parenchyma; f, cambium; g, wood or xyleni. 



