THE FLOWERS OF BRAZIL 



bills of a particular species ; so that we now understand why the 

 bills of these birds are sometimes short, sometimes long, sometimes 

 curved, and sometimes straight. 



The flowers must of course keep the honey intended for their 

 visitors in good condition ; they must not allow it to become diluted 

 with rain-water ; so they protect it by means of ingenious arrange- 

 ments of hairs, which turn the dripping rain aside. Moreover, they 

 even take measures of defence against uninvited visitors, who might 

 climb up the plant from the ground, and try to lick up the nectar 

 without conveying the pollen to other flowers. Just as our gardeners 

 protect their fruit-trees by rings of some adhesive substance, or 

 collars of downward-pointing spikes, so the plants surround their 

 flower-stalks with sticky rings, in order to prevent ants from approach- 

 ing nearer, or rows of thorns, to stop snakes ; or they buy such 

 creatures oflf by exuding another supply of nectar from the stem, 

 near the ground. There are even plants which induce the ants to 

 defend them against other unwelcome visitors, oflfering them food 

 or a dwelling-place in return for their services. 



Even the attitude of the flowers is not a matter of chance. The 

 majority of the flowers look up to the sky, since their visitors come 

 down upon them from the air. The Gampanulae, on the other hand, 

 look downwards, since in this position they are more likely to attract 

 the bumble-bees, which fly up from the ground, and are all the more 

 eager to visit the bell-flowers inasmuch as they have few competitors, 

 and can count on finding the larder full. The Orchids mostly look 

 out sideways, in order to enable hovering visitors, like the Humming- 

 birds, to reach their nectaries even while on the wing. And the flowers 

 which depend on the Hawk-moths assume the same position, for 

 these insects also feed while hovering. For creatures which are not 

 such expert fliers the Orchids prolong their lower petal into an 

 underlip. This offers the insect a convenient alighting-platform, from 

 which it can creep into the interior of the flower. Many Orchids 

 have developed the underlip into a sort of stool (Fig. 14, 5), on 

 which the visitor can perch while he comfortably inserts his trunk 

 into the flower. 



Even the scent which the flowers give out has been evolved for the 

 delectation of their visitors. While our own nostrils are able to 

 identify a number of flowers by their scent, the insects must have 

 a much more discriminating sense of smell, for they are able to 



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