92 TRACHEARY ELEMENTS 



7. De Baiy, pp. 155-171. 



8. Duerde'ii, 11., On the Occurrence of Vessels in Selaginclla. 

 Ann. Bot. 48 :459-465. 1984. 



9. Eames and MacDaniels, pp. 59-62, 64-67, 86-97, 150-153, 

 162-188. 



10. Esan, K., Vessel Development in Celery. Hilgardia 10 :479- 

 488. 1936. 



11. , , Ontoo-env and Structure of the Phloem of 



' Tobacco. liilcjardia 11 :343-424. 1938. 



12. Esau, K., and Hewitt, W. B., Structure of End Walls in Dif- 

 ferentiatintj Vessels. Hilgardia 13:229-244. 1940. 



13. Frost, F. II., Histology of the Wood of Angiosperms, I. The 

 nature of tlie pitting between tracheary and parenchymatous 

 elements. Bull. Torr. Bot. Club 56 :259-264. 1929. 



14. Haberlandt, pp. 302-325. 



15. Jeffrey, Ch. IV and VII. 



16. Kellog, E. S., Pulpwood and Woodpulp in North America. 

 N. Y., 1923. 



17. Stover, E. L., The Vascular Anatomy of Cahnnovilfa longi- 

 folia. Ohio -Jour. Sci. 24:169-179. 1924. 



