often preserve and renew the past for him in this way.
These leaves from my own journal are not very good samples of this sort of thing, but they preserve for me the image of many a day which memory alone could never have kept.
March 3, 1879. The sun is getting strong, but winter still holds his own. No hint of spring in the earth or air. No sparrow or sparrow song yet. But on the 5th there was a hint of spring. The day warm and the snow melting. The first bluebird note this morning. How sweetly it dropped down from the blue overhead!
March 10. A real spring day at last, and a rouser! Thermometer between fifty and sixty degrees in the coolest spot; bees very lively about the hive, and working on the sawdust in the wood-yard; how they dig and wallow in the woody meal, apparently squeezing it as if forcing it to yield up something to them! Here they get their first substitute for pollen. The sawdust of hickory and maple is preferred. The inner milky substance between the bark and the wood, called the cambium layer, is probably the source of their supplies.
In the growing tree it is in this layer or secretion that the vital processes are the most active and potent. It has been found by experiment that this tender, milky substance is capable of exerting a very great force; a growing tree exerts a lifting and pushing force of more than thirty pounds to the square inch, and the force is thought to reside in the soft
fragile cells that make up the cambium layer. It is like the strength of Samson residing in his hair. Saw one bee enter the hive with pollen on his back, which he must have got from some open greenhouse; or had he found the skunk cabbage in bloom ahead of me?
The bluebirds! It seemed as if they must have been waiting somewhere close by for the first warm day, like actors behind the scenes, for they were here in numbers early in the morning; they rushed upon the stage very promptly when their parts were called. No robins yet. Sap runs, but not briskly. It is too warm and still; it wants a brisk day for sap, with a certain sharpness in the air, a certain crispness and tension.
March 12. A change to more crispness and coolness, but a delicious spring morning. Hundreds of snowbirds with a sprinkling of song and Canada sparrows are all about the house, chirping and lisping and chattering in a very animated manner. The air is full of bird voices: through this maze of fine sounds comes the strong note and warble of the robin, and the soft call of the bluebird. A few days ago not a bird, not a sound; everything rigid and severe; then in a day the barriers of winter give way, and spring comes like an inundation. In a twinkling all is changed.
Under date of February 27, 1881, I find this note: "Warm; saw the male bluebird warbling and calling cheerily. The male bluebird spreads his tail as he flits about at this season, in a way to
make him look very gay and dressy. It adds to his expression considerably, and makes him look alert and beau-like, and every inch a male. The grass is green under the snow, and has grown perceptibly. The warmth of the air seems to go readily through a covering of ice and snow. Note how quickly the ice lets go of the door-stones, though completely covered, when the day becomes warm."