254 



are Stellale, the whole of the tissue is highly lacunose. The 

 veins are without mechanical tissue, but are accompanied by 

 colourless, long-celled bundle-sheaths. The hydathodes are 

 precisely similar in structure to those of S. nivalis, exactly 

 marginal, with convex epithema; they secrete no lime (Fig. 1С}. 



Fig. 7. Saxifraga hieraciifolia. 



A (З/2), Leaf-form. B, Transverse section of leaf. C, The same in longitudinal section 



(with hydathode). D, Spongy parenchyma. (B, C, and D s"/]). 



In its choice of localities this species probably nearly agrees 

 with S. nivalis. In its structure (as may be seen from the 

 above) it is more typically mesophytic than that species, the 

 whole of its mesophyll being even more loosely arranged. Its 

 means of protection against excessive transpiration are as slightly 

 developed as those in S. nivalis; it can be distinctly seen that 

 the palisade-tissue is less developed than in S. nivalis, — 



