VIII ILLUSTRATIONS. 



10. Chief physical divisions and geographical plan of South Australia, after Howchin and 



Gregory, with the 5-, 10-, and 15-inch isohyets. 



11. Graphs showing the annual (totdl) and "non-effective" rainfall for 1901-1906 at 



Oodnadatta (a), Copley (6), and Quorn (c), South AustraUa, based on records 

 supplied by the Adelaide office of the Commonwealth Bureau of Meteorology. 



12. Acacia linophylla, transverse section of phyllode, semi-diagranmiatic, X 72. The 



large proportion of mechanical tissue is indicated («c), and the protected 

 position of the chlorenchyma (ch). The relatively heavy covering of hairs 

 is indicated by the stippUng. 



13. Same. Detail of margin of phyllode to sho'y the nature of the sclerenchyma and 



epidermal cells and the presence of glandular trichomes, X 700. 



14. Same. Detail of inner portion of chlorenchyma showing its relation to the fibro- 



vascular bundle at the left, X 700. 



15. Acacia continua, transverse section of chlorophyll-bearing stem, X 52.5. 



16. Acacia tetragonophylla, cross-section of phyllode, semi-diagrammatic, X 85. 



17. Caswirina siricta, transverse section, semi-diagrammatic, of chlorophyll-bearing stem, 



X 72. The chlorenchyma is shown partly protected by the heavy epidermis 

 and partly by the furrows with the trichomes, of which the latter are not 

 shown. The enlarged outer ends of the sclerenchyma also act in the same 

 capacity. 



18. EremophUa alternifolia, detail of young stem with glandular trichome, X 52.5. 



19. Same. Transverse section of leaf showing old glandular trichome, heavy epidermis, 



and its covering of a resinous substance. 



20. EremophUa fredingii, semi-diagrammatic transverse section of leaf to show the size 



and frequency of internal glands {gl), X 52.5. 



21. EremophUa rotundifolia, longitudinal section, semi-diagrammatic, X 52.5, to show the 



relatively large internal glands and the very heavy covering of hairs (tr). 



22. Fusanus acuminatiia, fragment of leaf showing chlorenchyma and a group of tracheids, 



X350. 



23. Same. Cross-section of leaf to show the heavy epidermis consisting of two layers of 



cells, X 350. 



24. Gramllea stenobotrya, semi-diagrammatic transverse section of leaf. The various 



tissues are as indicated. Trichomes and stomata are confined to the ventral 

 side, X 52.5. 



25. Same. Detail of leaf, dorsal side, in cross-section, to show the greatly elongated 



epidermal cells and well-marked paUsades, X 350. 



26. Hakea leucoptera, leaf .fragment, in transverse section, with very heavy epidermis and 



deeply sunken stoma and papillate processes in stomatal canal. The presence 

 of sclerenchymatous fibers in the palisade chlorenchyma is shown. X 350. 



27. Hakea muUilineata, semi-diagrammatic cross-section of leaf. The prominent devel- 



opment of mechanical tissue and dorsiventral nature of the leaf structure are 

 indicated. X 52.5. 



28. Same. Fragment of leaf, cross-section, to show heavy epidermis, deeply sunken 



stoma, and pronounced palisade character of the chlorenchyma, X 350. 



29. PUtosporum phyllyrceoides, fragment of dorsal side of leaf, transverse section, to show 



the 2- or 3-layered epidermis, X 350. 



30. Same, ventral side of leaf. The heavy outer epidermal wall, the single cell layer of 



the epidermis, and the superficially placed stoma are indicated. X 350. 



31. Triodia irritans, transverse section of leaf, semi-diagrammatic, showing its infolded 



condition and the position and relative abundance of the main tissues, X 85. 

 In figures 12 to 31 the tissues are designated as follows: ch, chlorenchyma; fx, conductive 

 tissue; gl, internal gland; hd, hypoderm; sc, sclerenchyma; ep, epidermis; 

 fi), fibro-vascular tissue. 



