Primulaceae. 



197 



H. .Müller has found, by studying A. septentrionalis in 

 the Alps, that visits by insects (various Diptera) are not fre- 

 quent. The inflorescence, which consists of a few rather small 

 and insignificant flowers, attracts but few visitors, hence he 

 assumes, that the plant will often be dependent on self- 

 pollination. The proximity of the stamens to the stigma 

 (fig. If), .4) must greatly facilitate this. 



Anatomy. In its anatomical structure, the root of 

 A. septentrionalis, according to Decrock's description (p. 121), 





Fig. 16. Androsaces septentrionalis. 



A, transverse section of a root-branch ; (obj. 4, oc. 6). B, the peduncle ; a sector of a 



transverse section with a vascular strand ; (obj. 4, oc. 4). (öland.) 



seems to resemble closely that of A. maxima; no difference 

 was found between the main and the secondary roots. The 

 primary cortex is few layered and thin-walled, and perishes 

 quickly, with the exception of the innermost layer, the 

 endodermis. This consists of comparatively large cells, which, 

 during the development of the root, divide by radial walls, 

 so that the endodermis can keep pace with the considerable 

 growth of the central cylinder (fig. 16, A); the outline of 

 each original endodermal cell is marked by a cutinised lamella. 

 The young, root, provided with 2 hadromal rays, quickly 

 attains the characteristics of the secondary type; the one 



