Uraso had charge of the advance, and when they halted that day it was under the spreading shade of a tree that was a marvel to the boys, although Blakely said there were plenty of them in the southern part of the island.
This was a tree, with a large central trunk, the branches of which spread out in all directions, to distances which were fully fifty feet on each side, and at irregular intervals were straight stems which shot down straight to the earth, the lower[p. 66] ends of which took root and thus served as supports for the long branches.
The boys went around, examining it from all sides. "What is it?" asked the boys.
"It is the banyan tree," answered John. "This is not the only kind which exhibits this peculiarity. What is called the screw pine also sends down shoots in the same way."
"Well, does each of these vertical stems become a tree of itself?"
"In the case of the mangrove these aerials, as they are called, carry up the sap, and form leaves at their upper ends, long after the main trunk dies."
"Do you mean that these drooping branches carry up the sap in the opposite direction, after they take root?"
"Yes; but that is not so remarkable, when it is understood that the buds of all trees are, in a measure, roots, and perform the same functions as roots. The plum tree, and many others, will form roots out of the buds, if the latter are buried in the earth."
"I have heard about the orchids, as I believe they are called. Do they act in the same way?"