260 



Transactions. 



pairs. The leaflets are rounded or irregularly lobed, with entire margin. 

 A few of the leaves, the shorter ones, have only one leaflet. The flowering- 

 stems are 1-5 in. high, and usually bear a few small leaves, which have 

 usually only 1-3 leaflets (fig. 11). The root-system is well developed, 

 consisting of a main tap-root, which gives rise to numerous branches. 



Fig. 12. — Cardamine heteropkylla. Transverse section of portion of leaf ( x 175). 



guard-cell of stoma ; b, hair ; c, palisade tissue ; d, xylem ; e, 



/, spongjr parenchyma ; g, large epidermal cell. 

 Fig. 13. — Cardamine heterophylla. Upj^er epidermis in surface view (x 175). 

 Fig. 14. — Cardamine heterophylla. Lower epidermis in surface view ( x 175). 



a, small 

 ];^iloem ; 



Anatomy. 



Leaf (figs. 12-14). — Both the upper and the lower epidermis consist of 

 cells which vary considerably in size, both in section and in surface view ; 

 some of the cells are small, others very large, and slightly convex on the 

 outer surface, so that they project somewhat beyond the level of the other 



