COLOURS OF FLOWERS AS A MEANS OF ATTRACTING ANIMALS. 195 



dark-brown humus has accumulated. Above the dark mould of the forest-floor a 

 pale colour, such as that of the Bird's Nest {Neottia), of Monotropa, and of the 

 Toothwort (LathrcBo), and other saprophytic and parasitic plants, is plainly visible 

 from a distance. These plants would hardly be noticed in a green meadow. 



Zoologists are of opinion that animals, especially those which visit flowers to 

 carry oif honey and pollen, possess a highly-developed colour sense, and that the 

 visits which are paid by bees, humble-bees, butterflies, flies, and beetles are 

 materially influenced by the colour of the flowers. Difierent animals prefer 

 different colours, and there are actually certain insects to which some colours are 

 "pleasing", others " unpleasing ". The favourite colour of the honey-bee, for 

 example, is a deep violet-blue; pure blue and violet are also pleasing to it, yellow 

 is less sought after but not avoided. Towards green the bees are indiflferent, but 

 red is disliked and shunned and is the " unpleasing " colour as far as bees are con- 

 cerned. With regard to blue and violet it is quite true that these colours in flowers 

 act as excellent allurements for humble-bees and bees, especially for honey-bees, 

 and this is the more remarkable since, as already mentioned, blue flowers are not 

 by any means the most numerous. We can only accept the views of zoologists as 

 to red, up to a certain point, however. Flowers with purple-red or carmine-red 

 colour, as well as all the shades from these to violet, are eagerly visited by bees, 

 and therefore only scarlet-red, cinnabar-red, and the shades leading from them to 

 orange are to be regarded as unpleasing to them. 



In a garden bed close in front of the house where I live in summer a patch of 

 Pelargoniwm zonale, called by gardeners Scarlet Geranium, is planted. Near at 

 hand, on the other side of the path, there grows the narrow-leaved Willow-herb 

 (Spilohium angustifoliuTn). The scarlet-red flowers of the Geranium and the 

 violet flowers of the Willow-herb open simultaneously. Bees and butterflies 

 swarm and flutter hither and thither over them, but, strangely enough, the butter- 

 flies halt on both these plants and do not show especial preference for either. The 

 honey-bees fly past the scarlet flowers with indifference, and turn only to the violet 

 flowers of the Willow-herb. In the Vienna Botanic Gardens the bluish-violet 

 flowers of Monarda fistulosa and the scarlet Mona/rda didyina stand side by side 

 with the blue flowers of the Hyssop (Hyssopus officinalis). All three blossom 

 together about the middle of July. The honey-bees fly about there in large 

 numbers, but they only visit the Hyssop and violet-flowered Monarda, the scarlet 

 flowers of Monarda didyma being avoided by them. I purposely here say 

 "avoided" and not "disliked", because it is uncertain whether the absence of bee- 

 visits to scarlet flowers is caused really by an actual dislike of the scarlet colour, 

 or whether it is not rather colour-blindness which is known to be the reason why 

 many human beings do not see red. If we say that the honey-bees do not see the 

 scarlet colour it would be clear why they would pay no visits to the flowers of the 

 Scarlet Geranium and the scarlet Monarda. They would not notice them, because 

 the nerve-bundles which correspond to' the scarlet colour are wanting in their eyes. 

 This does not contradict the fact that other animals see this colour well, and that 



