104 



Knud Jessen. 



often show large slit-like lacunae on the dorsal side of the 

 leaf. Stereom is absent from the leaves. Fig. 39 (A,B, C, 

 D,E). 



At the apex of the leaf-teeth there is a slightly developed 

 epithema, below which tracheids terminate; water-stomata 

 occur upon the upper surface of the leaf-teeth on a limited area. 



The three bundles in the leaf-stalks of these two 



Fig. 39. 



Alchinnlla alpina from Greenland. A, Transverse section of leaf (""/J. B, Stoma ( 200 /,). C, 

 Epidermis of the upper surface of the leaf ( 10O /i). D, Epidermis of the lower surface of the 

 leaf with hairs and stomata C 200 ,]). E, Section of spongy parenchyma parallel to the surface 

 ( 200 /,). — AlchimiMa fœroensis. F, Transverse section of leaf-stalk ( 20 /i) ; ch, collenchyma ; e. 

 endoderrois ; I, leptome ; x, xylem ; I», "pith". 



species are concentric in structure. This peculiar feature 

 was first demonstrated by C. de Candolle 1 in a great many 

 Alchimilla-species, among others also in A. alpina and A. 

 minor, and afterwards Bouygues 2 , without mentioning 

 de Candolle's paper, has published a short note upon the 

 same subject. Buser 3 has been studying de Candolle's 



1 Bull, de l'herbier Boissier, T. I, 1893. 



2 Act. soc. Linn, de Bordeaux, 1900. 



3 Bull, de l'herbier Boissier, T. II, 1894. 



