524 T. Holm — Ceanothus Americanus and ovatus. 



Ceanothus Americanus L. 



Fig. 1. Seedling, natural size. E = the primary root with mycorhizse (M) ; 

 H = Hypocotyl ; Ep. = Epicotyl ; L— L = the two opposite leaves 5, L 3 and 

 L 4 = the succeeding, spirally arranged leaves. 



Fig. 2. A cotyledon, magnified. 



Fig. 3. A young plant in the second year, natural size. St. = the dead 

 stem of previous year ; the other letters as above. 



Fig. 4. A plant in the third year, natural size. Letters as above. 



Fig. 5. Transverse section of petiole of mature leaf ; Ep. = Epidermis ; 

 Coll. = Collenchyma ; M = a nrucilage-cell, x 240. 



