PLATE IL TYPES OF TWIGS AND PITH, 



1. Tulip Tree (alternate branching). 



2. Catalpa (whorled branching). 



S. White Ash (opposite branching). 



4. Gray Birch (slender and warty). 



5. Staghorn Sumach (hairy). 



6. Elderberry (lenticels prominent). 



7. Black Cherry (lenticels transversely elon- 



gated). 



8. Chestnut (lenticels small and numerous). 

 Drawings are about one-half natural size. 



9. Black Gum (lenticels few and inconspicuous). 



10. Black Walnut (chambered pith). 



11. Sumach (large pith). 



12. Sassafras (medium-sized pith). 



13. Oak (star-shai)ed pith). 



14. Black Alder (triangular pith). 



15. Common Locust (angular pith). 



16. Elm (circular pith). 



17. Birch (semicircular or irregular pith). 



