46 TYPICAL FLOWERS OF ALPINE PASTURES 



are so constructed that only certain kinds of insects 

 can reach the honey legitimately. It has also been 

 proved experimentally that certain insects favour a 

 flower of one colour, and will avoid or overlook a 

 flower of another. Blue flowers, for instance, are, 

 as a rule, "bee flowers," while many white flowers 

 are visited by small flies. It is therefore possible 

 that in many cases not only the colour, but the 

 increased density of the pigment, met with in Alpine 

 flowers, may be primarily due, not to the special 

 physical conditions of the Alpine world, but to a 

 specialisation in favour of a particular class of insect 

 visitor. 



In connection with the colours of Alpine flowers, 

 it may be remarked that certain species which 

 normally bear coloured flowers are occasionally found 

 to produce white flowers. We are all familiar with 

 the white Heather; and white forms of Alpine flowers, 

 such as of the Common Bell Gentian or a Bearded 

 Campanula, are equally prized on account of their 

 rarity in the Alps. The tendency to produce occasional 

 white flowers is greatest in those plants with blue, 

 pink, or red flowers, and least among the yellow- 

 flowered species. White-flowered plants will also 

 sometimes assume a yellowish hue. In others, again, 

 such as the Spring Crocus or the Field Pansy {Viola 

 tricolor, Linn.), the colours, or rather the combinations 

 of colours, of the flowers are always fluctuating. The 

 causes which lie at the root of these colour-changes 

 are complex, and are not yet fully understood. It is 



