The reason of the shade not being deep, nor the darkness profound, under these domes of verdure, was that these trees presented a curious anomaly in the disposition of the leaves. Instead of presenting their broad surface to the sunlight, only the side is turned. Only the profile of the leaves is seen in this singular foliage. Consequently the sun’s rays slant down them to the earth, as if through the open slants of a Venetian blind.
Glenarvan expressed his surprise at this circumstance, and wondered what could be the cause of it. Paganel, who was never at a loss for an answer, immediately replied:
“What astonishes me is not the caprice of nature. She knows what she is about, but botanists don’t always know what they are saying. Nature made no mistake in giving this peculiar foliage to the tree, but men have erred in calling them EUCALYPTUS.”
“What does the word mean?” asked Mary Grant.
“It comes from a Greek word, meaning I _cover well_. They took care to commit the mistake in Greek, that it might not be so self-evident, for anyone can see that the ecualyptus covers badly.”
“I agree with you there,” said Glenarvan; “but now tell us, Paganel, how it is that the leaves grow in this fashion?”
“From a purely physical cause, friends,” said Paganel, “and one that you will easily understand. In this country where the air is dry and rain seldom falls, and the ground is parched, the trees have no need of wind or sun. Moisture lacking, sap is lacking also. Hence these narrow leaves, which seek to defend themselves against the light, and prevent too great evaporation. This is why they present the profile and not the face to the sun’s rays. There is nothing more intelligent than a leaf.”
“And nothing more selfish,” added the Major. “These only thought of themselves, and not at all of travelers.”
Everyone inclined to the opinion of McNabbs except Paganel, who congratulated himself on walking under shadeless trees, though all the time he was wiping the perspiration from his forehead. However, this disposition of foliage was certainly to be regretted, for the journey through the forest was often long and painful, as the traveler had no protection whatever against the sun’s fierce rays.