The scent is more delicate still in insects. A bee flies directly to the flower that it wants to reach; a worm crawls to its leaf; a bedbug, a flea, a mosquito scents a man a hundred thousand of its steps away.
If the particles which separate from a substance and enter our noses are small, how small must be those particles that reach the organ of smell of the insects!
The Silkworm
I had some old mulberry-trees in my garden. My grandfather had planted them. In the fall I was given a dram of silkworm eggs, and was advised to hatch them and raise silkworms. These eggs are dark gray and so small that in that dram I counted 5,835 of them. They are smaller than the tiniest pinhead. They are quite dead; only when you crush them do they crack.
The eggs had been lying around on my table, and I had almost forgotten about them.
One day, in the spring, I went into the orchard and noticed the buds swelling on the mulberry-trees, and where the sun beat down, the leaves were out. I thought of the silkworm eggs, and took them apart at home and gave them more room. The majority of the eggs were no longer dark gray, as before, but some were light gray, while others were lighter still, with a milky shade.
The next morning, I looked at the eggs, and saw that some of the worms had hatched out, while other eggs were quite swollen. Evidently they felt in their shells that their food was ripening.
The worms were black and shaggy, and so small that it was hard to see them. I looked at them through a magnifying-glass, and saw that in the eggs they lay curled up in rings, and when they came out they