448 Physiologie, Biologie, Anatomie u. Morphologie (Systematik). 



1. Cortical cavities large. 



a. Hard bast well developed. 



A. Vessels of wood relatively large. 



(1) Section small. 5. E. cornuta. 



(2) „ large. 



(a) Epidermis very thick. 6. E. tetraptera. 



(b) „ thickisch and wood-curve slender. 



7. E. obliqua. 



(c) „ thinner and wood-cuTve thicker. 8. E. Gunnii. 



(3) Section of average size. 



(a) Section twice as broad as thick. 9. E. megacarpa.. 



(b) Wood-curve always entire and exceedingly thickened. 



10. E. macrorhyncha. 



(c) Wood-curve almost always entire and ordinarly thick. 



11. E, globulus. 



B. Vessels of wood small. 



(1) Section large and epidermis of average thickness. 



12. E. alpina, 



(2) „ of average size and epidermis thin. 13. E. viminalis. 



C. Hard bast poorly developed. 



A. Vessels of wood relatively large. 



(1) Section large, twice as broad as thick. 14. E. leucoxylon. 



(2) „ of average size. 



(a) Epidermis relatively thick. 15. E. grossa. 



(b) „ of average thickness. 16. E. occidentalis. 



B. Vessels of wood small. 



(1) Section twice as broad as thick. 



17. E. cornuta var. Lehmanni. 



(2) „ as broad as thick. 18. E. obcordata. 

 2, Cortical cavities small. 



a. Hard bast well developed. 



A. Epidermis relatively thin. 19. E. Stuartiana. 



B. „ of average thickness. 20. E- melliodora. 



b. Hard bast feebly developed. 



A. Wood-curve excessively thick. 21. E. amygdalina. 



B. Vessels medium-sized. 22. E. rostrata. 



C. „ comparatively small. 



(1) Epidermis thicker. 23. E. rudis. 



(2) „ thinner. 24. E. tereticornis, 

 B. Leaves unequally green on both sides. 



1. Cortical cavities large. 



a. Hard bast well developed. 



A. Wood-curve exceedingly thickened. 25. E. gomphocephala. 



B. „ „ slender. 26. E. marginata. 



b. Hard bast feebly developed. 



A. Vessels moderately large and numerous. 27. E. saligna. 



B. „ small and few. 28. E. punctata. 



2. Cortical cavities small. 



a. Comparatively numerous. 29. E. corynocalyx, 



b. Relatively few and very small. 30. E. diversicolor. 



Die letzten fünf Tafeln enthalten je sechs Durchschnitte, die erste 

 Abbildungen allgemeineren Inhalts. 



Die Beschreibungen sind sehr eingehend und geben genaue Zahlen 

 für die einzelnen Grössenverhältnisse; am Schlüsse jeder Diagnose finden 

 sich die charakteristischen Eigenschaften der betreffenden Art noch einmal 

 zusammengestellt . 



E. Roth (Halle a. S.). 



