198 THE SCENT OF FLOWERS AS A MEANS OF ATTRACTING ANIMALS. 



sinks to its lowest point in late autumn. Yellow reaches a first maximum in May, 

 falls somewhat during the summer, and reaches a second maximum in October. 

 The curve of red takes a low position in early spring, rises uniformly through the 

 summer, and reaches its highest point in September. The curves of violet and blue 

 show no large variations through the whole period of vegetation, but two maximal 

 points are to be seen in them, just as in the yellow, one in spring, and the other in 

 autumn. 



This particular seasonal change of the prevailing flower-colour, of course, only 

 holds good for the Baltic flora. Even in the adjoining Mediterranean flora the 

 colour-curves are somewhat different, and the deviations are greater still in the 

 flora of corresponding latitudes in North America. Nothing can be said of the 

 predominance of certain colours during the vegetation period in the Alpine 

 flora, for on the heights above the tree-line there is actually no spring and no 

 autumn, only a short summer following a long winter. All the flowers have 

 therefore to blossom in this short time, and all the flower-visiting animals must 

 do their flying about during the short period which is free from snow, if they do 

 not wish to starve. Hardly is the snow melted when there appear almost simul- 

 taneously the violet bells of the Soldanellas and the golden flowers of the Cinque- 

 foil (Soldanella and Potentilla), the white Crowfoot and Androsace, the red Silenes 

 and Primulas {Ranunculus alpestris, Androsace obtusifolia, Silene acaulis, Primula 

 minvma), the blue Gentians and the yellow Auriculas (Gentiana acaulis, verna, 

 Primula Auricula), the heaven-blue Forget-me-not and the yellow Violet (Myosotis 

 alpestris, Viola biflora) as well as the Saxifrages in every conceivable colour. On 

 looking at the varied flowers, which have been drawn from nature by E. Heyn 

 at my request, and reproduced in the accompanying Plate XII. entitled "Alpine 

 Flowers in the Tyrol," it will be seen at once that every colour is to be met with 

 here. White and red, yellow and blue, brown and green stand in varied combina- 

 tion side by side on a hand's-breadth of space. The bees, humble-bees, flies, and 

 butterflies which are dependent on the honey and pollen of these flowers may also 

 be seen in Alpine regions flying about at this same time. If one of these animals 

 should be late, its existence is endangered on account of the briefness of the period 

 of vegetation, for should it not happen that some belated flower blossoms in a hollow 

 where the high-piled winter snow has lingered for a long time, the animal is in 

 imminent risk of perishing from lack of food. 



THE SCENT OF FLOWEES CONSIDERED AS A MEANS OF 

 ATTRACTING ANIMALS. 



The scents of flowers, like their colours, are very intimately connected with 

 the Animal Kingdom. The scent of foliage, stems, and roots, as mentioned else- 

 where (vol. i. p. 431), serves very efficiently to frighten and ward off herbivorous 

 animals; but the scent emitted from the flowers, on the other hand, serves to allure 

 such animals as transfer the pollen from flower to flower and from plant to plant 



