What a world this would be to us had we microscopic vision! A thousand times as many beasts to look at, a thousand times as many things to see and understand!
ANT GATHERING NECTAR FROM LEAF NECTARIES OF THE CHINESE WOOD-OIL TREE
A year ago I planted in my garden in Maryland three young wood-oil trees from the Yangtse valley of China, broad-leaved trees something like the catalpa. Just where the leaf stem joined the leaf blade there were two curious, dark red, oval glands. The use of these I did not understand until one morning I discovered a big black ant on each leaf, and each ant was stationed at the base of its leaf near these glands and evidently was lapping up from them small drops of nectar which kept oozing out from the center of each gland.
These rapidly-walking little creatures, which spend their time roaming everywhere, had discovered the use of these nectar glands although they were on the leaves of a plant which they had never seen before.
Whenever I touched a leaf the ant upon it ran about as if to frighten an intruder away, and I could not help but wonder if in China, where the wood-oil tree is at home, there might not be some stinging ant which takes upon itself to protect the foliage from the attacks of caterpillars, and gets, in payment for its labor, the nectar from these glands. The tropics are full of such agreements between the plants and the ants, and very effective ones they are, too.
The photograph shows a black ant with antennæ extended, reaching over one of these big glands for the drop of nectar which glistens just below its head. On the other gland, just back of the ant’s left antenna, a second drop of nectar can be seen.
First one and then the other of these nectaries is licked clean by the ant, and so well was the work done that throughout the summer it was only when I visited the leaves in early morning, before the ants were out, that I could find the beads of nectar in their places in slight depressions in the glands.