230 



On account of the styles beini;: directed towards the two 

 outer (median) stamens, it is these only, which will be instru- 

 mental in effecting pollination. The two lateral stamens will 

 scarcely ever come into contact with the stigmas ; they become 

 useless organs, which may, perhaps, be connected with the 

 fact that they sometimes become rudimentary. 



Clirysosplenium alternifoUmn v. tetrandrum is the most 

 reduced type among the Saxifragaceœ\ here, as in other instances, 

 there is correlation between this and the small size of the 

 flower. 



Summary. 



As the more general results of the investigations given 

 in detail above, the following points may be mentioned. 



I. Structure of stem. The species belong to several 

 growth-formis, viz. the following: — 



A. To the Primula-type belong: S. hier actif olia, S. nivalis 

 and S. stellaris. They have, as is the case in many species of 

 Primula^ a vertical, sympodial rhizome, with leaves in a rosette. 

 The primary root dies early, and numerous adventitious roots 

 are developed. The inflorescence is borne upon a leafless 

 peduncle. The age and length of the rhizome here, as in 

 other instances, is evidently dependent upon the dampness of 

 the soil ; the damper it is, the quicker does the rhizome die 

 away at the hinder end. The rejuvenating shoots occur in the 

 axils of the upper leaves of the rosette, the most vigorous in 

 the axil of the uppermost leaf, while the others are weaker the 

 farther down they occur. Sometimes, in the axil of the upper- 

 most foliage-leaf, a lateral, floral shoot is developed even in 

 the year the parent shoot flowers ; this relegates the uppermost 

 rejuvenating shoot to the axil of the leaf next below. 



