20 Forestry Quarterly. 



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der Phanerogamen, hauptsachlich der Leguminosen. Berichte, d. 

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12. Kohl. Zur Wasserleitungsfrage. Bot. Zeit., 1885. 



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holzer. Sitzb : d. Akad. Wiss. Wien, vol. LXXVI, 1878. 



14. Nageli, C. Ueber den innern Bau Vegetabilischer Zellenmembranen. 



Sitzgs. Ber. d. Konigl. bayer. Akad. d . Wiss., 1864. 



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1887. 



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Description of Plate II. 



Fig. I. Tangential section of Sequoia showing sectional view of bor- 

 dered pits. The membrane and torus are seen to occupy a median po- 

 sition between the two arching cell walls. X 1200. 



Fig. 2. Tangential section of hard pine showing sectional view of bor- 

 dered pits. The tori have been pressed against the left hand orifices by 

 excessive pressvire. X 1000. 



Fig. 3. Tangential section of hard pine showing sectional view of bor- 

 dered pits. The torus in this case is thin and flexible and has been jam- 

 med into the right hand orifice so firmly that it appears bow-shaped. 

 X 1000. 



Fig. 4. Tangential section of freshly cut green white pine sapwood in- 

 jected with a carbon mass. The minute carbon particles are seen to pene- 

 trate from one cell to another by the bordered pits. X 700. 



Fig. 5. Tangential section of Sequoia heartwood, showing the penetra- 

 tion of carbon mass from one tracheid to another through the numerous 

 bordered pits. X 500 



Fig. 6. Tangential section of the summer wood of a common long- 

 leaf pine paving block. The heavy tar oils are seen to penetrate by means 

 of the bordered pits. X 600. 



Fig. 7. Diagrammatic drawing of pit membrane and torus. The per- 

 forations are seen to occur in the thinner bands of membrane substance. 

 X 3500. 



Fig. 8. Radial section of freshly cut green white pine sapwood treated 

 with a carbon mass. The carbon particles are seen to penetrate the pit 

 membrane in a rim about the torus and in lines radiating outward from 



it. X 1500. r ■ ■ y. -s. 



Fig. 9. Radial section of larch showing large perforations m the pit 

 membranes. X 800. . ,, 



Note.— With the exception of Fig. 7 these illustrations are unre- 

 touched" photomicrographs. 



