ani] THE MECHANISMS OF FLOWERS. 243 
(Amygdalus Persica, Cydonia japonica). In this relation the 
- genus Geum is interesting ; for that species which is fertilised by 
bees (G. rivale) exhibits a red colour in which the influence of the 
primitive yellow is still evident. 
Rosaceve visited for the sake of their pollen have white flowers 
when their chief visitors are small, short-lipped insects (Spirwa 
Ulmaria, S. Aruncus) ; but show a tendency to red when frequented 
~ mainly by bees or Syrphide (Rosa). In the whole order of Rosacez 
‘no species seems to have acquired a violet or blue flower, nor to have 
_ become adapted exclusively for fertilisation by Lepidoptera. 
Orv. SAXNIFRAGACE. 
Tribe Saxi/ragee. 
_ Dr. A. Engler? has investigated thirty-eight species of Saaifraga 
and found them to be all proterandrous with movement of the 
amens singly in succession towards the middle of the flower. 
“On the other hand, he found Bergenia (Saxifraga crassifolia, L.), 
Mitella, L., Heuchera, L., and Drummondia, DC. (= Mitella pent- 
andra, Hook.) to be proberogynous without movement of the 
tamens (221). On species of Saxifraga flowering in the open air 
_ he observed beetles (Haliica, small Staphylinee), flies, and especially 
bees. He doubts Sprengel’s interpretation of the so-called honey- 
e ides (Saftmal), for though present in some Saxifrages they 
‘ re absent in others. In plants whose honey varies between 
ully exposed and hidden situations, such a fluctuation of the 
: Bate marks is very natural, and rather strengthens Sprengel’s 
Cory. 
In my Alpendlumen I have tried to prove that those species of 
axifraga which have dotted petals show all transitions from mere 
: eament by which insects are attracted to ornamentation which 
arves also as a “ pathfinder.”’ 
The proterandrous flowers of S. aizoides, L., and S. oppositifolia, 
| L,, are figured by Axell (17). 
| Saxifraga sarmentosa, L. fil., has asymmetrical flowers (Todd, 
| 722). . , 
_ Of the numerous Alpine species of Saxifraga, I have examined 
and figured thirteen. All show, more or less distinctly, the 
seculiarity that the anthers ripen one after another; at the same 
iP 
| 
| 
f 
1 “** Monographie der Gattung Saxifraga,” p. 26. Breslau, 1872. 
R 2 
