1899] THE FLORA OF THE ALPS 1 1 1 



bright colour of flowers is to attract insects. We find it in flowering 

 plants where it can have no such function, as in the scarlet stigmas of 

 the hazel, which is unquestionably anemophilous, and in the young 

 inflorescence of the larch ; or, in Cryptogams, more especially in con- 

 nection with the organs of reproduction, as in the brightly-coloured 

 oogones and antherids of Char a and the red sporanges of Sphagnum. 

 There can be little doubt that the bright red colour has an important 

 function in absorbing and retaining the heat-rays, and thus maintain- 

 ing the organ at a temperature necessary for the physiological processes 

 going on within it. Hence the very earliest of the flowers of the 

 Alps, like Soldanellas and Hepaticas, are usually very brightly coloured, 

 and the earliest spring foliage has also very commonly a more or less 

 bright red tint. 



There are other and equally interesting characteristics of alpine 

 plants. And here it may be worth while to contrast the conditions of 

 life in high altitudes and in high latitudes, which are often assumed 

 to be very similar. They are, in truth, totally different. In the 

 arctic or subarctic zone we have a brief summer, during which there is 

 almost perpetual insolation and a nearly uniform temperature through- 

 out the twenty-four hours ; in Switzerland the summer nights are 

 longer than they are with us, and the difference of temperature between 

 day and night is often excessive, the nights being associated, even in 

 the height of summer, with exceptionally heavy dews. It will be 

 seen, therefore, that we have totally different climatic conditions to 

 deal with. We have in our own flora several arctic species which do 

 not occur in Switzerland, as, for example, Saxifraga nivalis and Primula 

 scotica. 



Alpine plants have several other characteristics besides the large 

 size or close crowding of the flowers. In the first place, although 

 many ripen abundance of seed, but a very small proportion, as has 

 already been mentioned, are annual. In many the floral organs are 

 almost completely formed within the flower-bud during the preceding 

 autumn, so that they are ready to unfold with the first warm days of 

 spring, and before the appearance of the leaves, not requiring these 

 organs to supply them with any further food-material. Hence the 

 very early flowering of many alpine and sub-alpine plants, such as 

 the hepatica, Christmas rose, winter aconite, species of Soldanella, 

 Primula, Gcntiana, etc. Secondly, from the great strain to which 

 they are subject from violent winds, we find a considerable number 

 with prostrate woody stems, species of willow, birch, etc, such as we 

 seldom meet with in plants of our own climate. For the same reason 

 the root-system is also often very strongly developed in comparison 

 with the aerial part of the plant. Furthermore, the extreme bright- 

 ness of the sun during the summer months has a tendency to cause 

 excessive transpiration or evaporation from the leaves, which has to be 

 counteracted by specialities of structure. This protection is afforded 



