34 SAGACITY AND MORALITY OF PLANTS. 



sweetly-perfumed flowers, like the Rose, Lily, Sweet- 

 Pea, etc. ; others have flowers not conspicuous either 

 for colour or perfumes, like those of the Nettles, 

 Grasses, etc. These two groups are relatively called 

 EiitomopJiiloiis and AnevwpJiilous flowers. No more 

 brilliant discovery was ever made in botany than 

 that which furnished the key to unlock the secrets 

 of this floral difference, which is based upon the 

 known fact that " crossing " is not only beneficial, 

 but in most cases absolutely necessary. There are 

 only two agents which are equal to the task of 

 effecting such cross -fertilisation, the insects and the 

 wind. The former visit flowers, many of them — such 

 as bees, butterflies, moths, etc. — getting their living 

 in no other manner. Their bodies are covered with 

 hair, and the /^//^;? -grains discharged from the ripe 

 stamens stick to them, and are thus carried from one 

 flower to another. As an insect on the wing usually 

 prefers visiting the same kind of flowers (at least 

 bees do), it follows that crossing must in this way be 

 brought about. In order to render the services of 

 insects more effective, the pollen -grains of flowers 

 they are in the habit of visiting are usually roughened 

 all over, so as to enable them to stick the better. 

 We can therefore understand the utility of colour 

 and perfume in flowers, and perceive how serviceable 

 to them such qualities must be, inasmuch as they 

 attract insects to fertilise them. 



For the same reason we apprehend why grasses 



