EXPLANATION OF FIGURES. 



Fig. 1. Xicutiana Tabacum. 

 Fig. 2. Xicotiana sylvestris. 

 Fig. 3. X. Tabacum x X. sylvestris. (Photographs of the three plants taken 



soon after they began to blossom.) 

 Fig. 4. Flowers and flower parts of; (a.) Xicotiana alata: (b.) X. Tabacum: 



(c.) Hybrid. 

 Fig. o. Flowers and flower parts of; (a.) X. Tabacum: (b.) X.. sylvestris: 



(c.) Hybrid. 

 Fig. 6. Leaves of; (a.) X. Tabacum: (b.) X. sylvestris: (c.) Hylirid. 

 Fig. 7. Xicotiana alata at maturity. 

 Fig. S. X. Tabacum x X. alata at maturity. 

 Fig. 9. Cortex, wood and pith of X. Tabacum. 

 Fig. 10. Cortex, wood and pith of X. sylvestris. 



Fig. IL Cortex and portion of wood and pith of X. Tabacum x X. sylvestris. 

 Fig. 12. Cortex, wood, and pith of X. alata. 

 Fig. 13. Cortex, wood, and pith of N. Tabacum x X. alata. 

 Fig. 14. Cross section of anther of X. Tabacum x X. sylvestris. 

 Fig. 1.5. Cross section of X. sylvestris anther. 

 Fig. 16. Cross section X. alata corolla. 

 Fig. 17. Cross section X. alata calyx. 

 Fig. IS. Cross section X. Tabacum x X. alata corolla. 

 Fig. 19. Cross section X. Tabacum x X. alata calyx. 

 Fig. 20. Cross section X. Tabacum corolla. 

 Fig. 21. Cross section X. Tabacum calyx. 

 Fig. 22. Cross section X. alata leaf lamina. 

 Fig. 23. Cross section X. Tabacum x X. alata leaf lamina. 

 Fig. 24. Cross section X. Tabacum leaf lamina. 

 Fig. 25. Cross section X. Tabacum x X. sylvestris leaf lamina. 

 Fig. 26. Cross section X. sylvestris leaf lamina. 

 Fig. 27. X. Tabacum starch grains. 

 Fig. 28. X. Tabacum x X. sylvestris starch grains. 

 Fig. 29. X. Sylvestris starch grains. 

 Fig. 30. Cross section X. Tabacum anther. 

 Fig. 31. Cross section X. Tabacum x X. alata anther. 

 Fig. 32. Cross section X. alata anther. 

 Fig. 33. Radish parent soon after beginning to blossom. 

 , Fig. 34. Kohlrabi parent soon after beginning to blossom. 

 Fig. 35. Hybrid between Radish and Kohlrabi soon after beginning to blossom. 

 Fig. 36. Hybrid between Radish and Kohlrabi at maturity, showing roots and 



lower part of stem. 

 Fig. 37. a. Cross section of Kohlrabi root. 



b. Cross section of Kohlrabi stem through thickened portion. 

 Fig. 38. a. Cross section of Radish root. 



b. Cross section of Radish stem corresponding to 97b. 

 Pig. 39. u. Cross section of Radish x Kohlrabi root. 



b. Cross section of Radish x Kohlrabi stem corresponding to 37i. 



