138 THE FERTILISATION OF FLOWERS. [PART ITI. 
I have observed on the Alps. Alsine verna, Jacq., Cherleria sedoides, 
L., and Mehringia muscosa, L., are so markedly proterandrous, that 
spontaneous self-fertilisation can only rarely and exceptionally take — 
place in them. Arenaria biflora, L., and Cerastiwm latefolium, L., 
also ripen their anthers before their stigmas, but, im default of — 
insect-visits, fertilise themselves. 
I found Stellaria cerastoides, L., to be homogamous, in which | 
respect it stands alone among the higher Alpine Alsinez. 
As bees are scarce in the higher regions of the Alps, Diptera — 
take their place as cross-fertilisers of the Alsine more than in the — 
lower grounds, and were alone observed on several of the above-_— 
mentioned species (600). 
Dr. T. Ludwig of Greiz has recently made the interesting 
discovery that most if not all of the distinctly proterandrous 
Alsinez are also gynodicecious; and that the plants with small and 
purely pistillate flowers are chiefly in bloom at the beginning of the © 
flowering-period of the large-flowered hermaphrodite plants. So 
these subsidiary pistillate plants make up for the preponder- 
ance of the staminate condition in the hermaphrodite flowers at 
that time (426, 427). 
Orv. CARYOPHYLLEZ; c. POLYCARPEZ. 
Polycarpon tetraphyllum, L., has cleistogamic flowers (Batalin, 
40). 
REVIEW OF THE CARYOPHYLLE2. 
The Caryophyllee exhibit an interesting series of gradations 
in the concealment of their honey, while the anthers remain 
throughout fully exposed ; a comparison of their insect-visitors will 
thus show what effect differences in the situation of the 
honey produce. 
The flowers of Alsinew, and the short and wide flowers of | 
Gypsophila paniculata, which all expose their honey freely, are 
chiefly frequented by flies and by a few beetles and other short-— 
lipped insects; when visited by bees, it is either by the least 
specialised forms (Prosopis, Halictus, Andrena) or by the most 
specialised and most diligent (Apis). Lychnis flos-cuculi, whose 
honey is hidden 9 to 10 mm. deep, and beyond the reach of short- 
lipped insects, is almost exclusively visited by highly specialised 
