“Why do flowers want insects?” asked Annie.

“Because they want their yellow dust taken from one flower to another, to ripen their seeds, or to fertilize them, as it is called.  The seeds are far better if they are ripened by the pollen or dust of another blossom than by the pollen of their own flower.  The bees, as you know, get covered with this dust as they visit one flower after another; some of it sticks to the bees, but a great deal of it drops off as they rub against the flowers.”

“It’s give and take,” said Jack.  “The flowers give the honey for the insects to eat, and the insects carry their pollen away for them.”

“Yes, that’s something like it,” said grandmamma.  “And now you can see why flowers which bloom at night need to have a strong odour.  There are some plants which

    ‘Keep their odours to themselves all day’

but towards evening they

    ‘Let the delicious secret out;’

and it is that moths and insects that fly about at night may know whereabouts the flowers are.  The bees are busy in the day-time; but there are a great many kinds of moths, in fact there are more moths than there are butterflies, and they only fly about at night, and the honey of flowers is their sole food.  So you see the scent of flowers has a great use.”

“I never thought of that before,” said Mary.

“If the flowers which keep open late in the evening have not a very strong perfume, they are generally white or pale yellow, so as to be seen easily.  There is one of these plants called the evening primrose—­not that it is like a primrose except in colour—­at the bottom of the garden walk.”

“Do let us go and see if there is a moth on it, grandmamma.”

Grandmamma smiled and said, “Jack might go and look, and then he could tell his sisters what he saw.”

Jack scampered away, and after a minute or two he was back with the report that he had counted seven winged flies and moths all busy feeding upon the honey of the different blossoms of the plant!

“Insects can smell things at a far greater distance than we can,” said grandmamma.  “The sense of smell seems to be their strongest sense.”

“Do you think it is a good thing to be able to smell so very much, grandmamma?”

“Certainly I do.  I know a keen sense of smell is sometimes disagreeable for its owner; but as a rule, when a smell is unpleasant it is unwholesome, and the nose is like a sentinel that gives warning of danger, so that we may either get out of the way or remove the cause.  Some people really seem to have no noses, considering what they will endure in the way of bad smells, and how careless they are about keeping windows shut that ought to be opened to let in the fresh air and sunshine.

“You must remember, children, that your five senses are but doors which the mind must keep open.  It is the mind that perceives.  We say, ’I perceive this apple is sour;’ ‘I perceive this cloth is rough;’ ’I perceive a smell of roses;’ ‘I perceive this flower is white;’ ’I perceive the birds are singing.’  So the word ‘perceive’ will do for tasting, feeling, smelling, seeing, and hearing.”