? 5 

 5? 



374 G. T. HARRIS ON SCHISTO&TEGA OSMVNDACEA MOHR. 



30. Haberlandt, G. Zur Physiologie der Lichtsinnesorgane der 



Laubblatter. Jahrh. fur. wiss. BoL, 1909. 



31. Wager, H. Perception of Light in Plants. Annals of 



Botany, Vol. 23, No. 91, July 1909. 



32. ScHiMPER, A. F. W. Plant Geographij. Oxford, 1903. 



Description of Plates. 



Plate 23. 



Fig. 1. Schistostega osmundacea Mohr. Fertile plant, x 16. 



,, 2. Distal end of protonema producing gemma, x 300. 



3. Perichaetium showing ball and socket arrangement, x 35-. 



4. Immature seta and calyptra. x 35. 



5. Gemma with separation cell, x 300. 



6. Gemma producing protonema. x 300. 



7. Gemma producing protonema. x 300. 



8. Gemma producing new gemma, x 300. 



9. Bipinnate arrangement of protonema. x 200. 

 ,, 10. Nodular condition of protonema. x 300. 



,, 11. Flask cell, with " rosette " chloroplast at A. x 300. 



Plate 24. 



Fig. 1. Protonema with flask- cell s : A. budding gemma; 

 B. early stage of flask cell ; C. " rosette " chloroplast 

 in base of flask-cell, x 300. 



2. Cells of leaf with chloroplasts. x 510. 



3. Photo-synthetic system with chloroplasts. A. budding 

 light-cell. X 510. 



4. Bowl-shaped chloroplasts in light-cells, ver. sec. x 510. 



5. Budding light-cell with migrating chloroplast at A. x 510. 



6. Four light-cells showing various stages in the division 

 of the chloroplast from a simple plate-like form com- 

 mencing division to the bowl-shaped chloroplast of four 

 pieces, x 510. 



,, 7. Bud of new plant arising from protonema. x 300. 



Figures in Text. 



Fig. 1. Plan of " The Shepherd's Hut," Dartmoor. 

 ,, 2. Photo-synthetic system of light-cells (after Noll). 

 ,, 3. Diagram of light-rays in obconical light-cell (after Noll). 



Jiiurn. Quckitt ilicroscojncal Club, Sir. 2, Vol. XIII., No. 82, AprU 1918. 



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