The more closely we approach the torrid zone, it is said, the greater is the number of bats and the richer their variety. The South is the native country of the majority of wing-handed animals. Even in Italy, Greece, and Spain, the number of bats is surprising. There, according to Brehm, who studied them industriously, as evening draws nigh they come out of their nooks and corners not by hundreds but by thousands. Out of every house, every old stone wall, every rocky hollow they flutter, as if a great army were preparing for a parade, and the entire horizon is literally filled with them. The swarms of bats one sees in a hot country are astonishing. They darken the sky. Everywhere there is a living and moving mass flying through the trees or gardens and groves. Through the streets of the town, through houses and rooms flits the moving train. Hundreds are constantly appearing and disappearing and one is always surrounded by a hovering swarm. A feature of the wings of bats, is a highly elastic skin. The outer layer is constantly kept pliable by anointing with an oily liquid, secreted by glands in the animal's face. The structure of the hair is also remarkable, as each thread presents under the microscope a screw-like appearance. THE COMING OF SPRING. E. E. BENTON. No one perhaps ever lived who excelled Henry D. Thoreau as a general observer of nature. He patiently and with minute care examined both animate and inanimate creation, and wrote down an accurate account of his observations, noting particularly the effects produced by the changes in the seasons. He worked diligently to discover the first sign of spring, with results not wholly satisfactory. In one place he asks: "What is the earliest sign of spring? The motions of worms and insects? The flow of sap in trees and the swelling of buds? Do not the insects awake with the flow of the sap? Bluebirds, etc., probably do not come till the insects come out. Or are there earlier signs in the water, the tortoises, frogs, etc.?" He found that whenever there was a warm spell during the winter some forms of vegetation, particularly the grasses and water plants, would begin to grow, and some would even bloom in favorable locations, as the skunk cabbage. He did not fully settle the question as to what would begin to grow first in the spring, whether it was the catkins of the swamp willow or the stems and leaves of the equisetum in the pool, or something else.