283 



In many of the cells of the mesophyll there are quantities 

 of tannin, which gives the usual reaction with iron. Besides 

 these scattered tannin-idioblasts there are found, precipitated 



Pig. 27. Saxifraga Aizoon. 



The epidermis of the leaf: A and B. Upper surface. C, Lower surface (S large sphaero- 



crystal is seen immediately beneath the epidermis, probably precipitated by alcohol. D 



and E, Lower surface (C »-s/,), {A, B, D, E ^k). 



