234 



those of the other flowers, and in S. cernua the terminal 

 flower is often the only one which is developed. 



Irregular flowers occur in S. cernua^ S. oppositifoUa and 

 (S. rivularis. 



V. Pollination. The flowers have colour, and honey 

 is secreted by the base of the pistil; in some instances scent 

 has been noted. Insect-visitors have been observed in several 

 of the species in Spitzbergen and Nova Zembla, especially by 

 Ekstam, and in the mountain regions of Northern Europe by 

 LiNDMAN, SiLÉN, Skottsberg aud Sylvén. 



Protandry is so common in the genus Saxifraga that 

 Engler (Bot. Zeitung, 1868, and in his "Monographie der Gattung 

 Saxifraga") even gives it as a generic character; that is also one 

 of the reasons why he refers S. crassifolia and other proto- 

 gynous species to the genus Bergenia. The nine species of 

 Saxifraga mentioned by H. Müller in "Alpenblumen" are also 

 nearly all decidedly protandrous, some protogynous species 

 are however mentioned {S. muscoides^ S. androsacea, S. Sequieri), 

 and one, viz. S. oppositifoUa, oscillates between slight protogyny, 

 slight protandry, and homogamy. To these Müller afterwards 

 added S. tridactylites as protogynous, while Sprengel found it 

 to be protandrous. 



The above-mentioned Arctic species give further proof that 

 protandry is not a generic character; true, it occurs most 

 commonly, but, firstly, it appears usually to be somewhat 

 slighter — at least than it is in many cultivated species which 

 I have observed in the Hortus Hafniensis, almost all of which were 

 decidedly protandrous ; usually, they become very soon homo- 

 gamous : I have observed protandry in *S'. aizoides, Aizoon, cer- 

 nua, groenlandica, hieraciifoUa, Hirculus, nivalis, rivularis, 

 stellaris and fricuspidata, as also in Crysosplenium. Secondly, 

 the same species often varies, being either prolandrous-homo- 

 gamous, or homogamous from the first. S. groenlandica, hie- 

 raciifolia, nivalis, rivularis, stellaris, tricuspidata and Chryso- 



