PLATE XIX. 



Koeberlinia spinosa. 



Fig. 1. Medullary rays, showing longitudinal extension, longi-tangential 

 section. Semi-diagrammatic, x 55. 



Fig. 2. Portion of (1) in detail, showing thick walls, some pits, and nu- 

 merous aerating places. Tangential, x 283. 



Fig. 3. Single medullary ray cell from (2), showing food bodies F, B; 

 pits, P; aerating spaces, A. Longi-tangential. x 636. 



Fig. 4. Medullary ray cells, showing one elongated and narrow cell e. c, 

 and some more, box-like, for storage, St. Longi-radial, x 283. 



Fig. 5. Single storage cell from (4), showing food bodies. Longi-radial, 

 X 636. 



Fig. 6. Portion of medullary ray extension in phloem region, showing 

 thin, unpitted walls and cells filled with nitrogenous material. Longi- 

 radial, X 283. 



Fig. 7. Portion of older wood, showing tracheids, Tr; fiber tracheids, 

 Ft, and wood fibers, wf. Cross, x 283. 



Fig. 8. Detail of (7), showing pitted condition of wood. X 636. 



Fig. 9. Water vessels bordering pith. Tr, tracheal tubes; Td, tracheid; 

 P, pith. X 636. 



Fig. 10. Spiral tracheids, near pith. Semi-tang., x 283. 



Fig. 11. Portion of wood, showing scattered tracheids, Tr. Cross, X 283. 



