I am no technical botanist, yet I have had pleasure untold when wandering in canyon, mountain, plain, forest, seaside, and desert in seeking to learn all I could of the flora of the region. When botanists said that the _cereus giganteus_--the giant suahuaro--was not to be found in California and I knew I had seen it growing on the California side of the Colorado River, there was great pleasure in photographing the few specimens I knew in this habitat and then in hunting for more. How well I remember one day climbing up hill and down, over rocky ridges and dangerous trails and places where there were no trails at all, every now and again seeing fresh specimens, _in California_, of this cactus "that did not grow in California." And when, at last, I stood on a ridge, looking down into a secluded canyon, where there were a dozen or more (which I photographed), I felt as if, humbly though it was, I were being used as an instrument for increasing the botanical knowledge of the world. CHAPTER XII RADIANCIES OF JOY, INSPIRATION, AND SERENITY I want to radiate the healthfulness of joy. Joy is the sunshine of the soul. Let it shine. If there is so much of it that it fills the soul, it makes of it a luminous body that must radiate light and warmth and health to others. The joyous man is the healthy man, and he that has health should joy to give it to others, whenever and wherever he can. My friend, Marshall P. Wilder, was a radiating center of joy as well as fun. He was funny, but he was more--he was joyous. There was no enmity, no malice, no unkindness, no cruelty in his fun; it was all healthful, kind, sane, and joyous. A little girl once said of a certain man: "I like that man because he always _shines_ at me." Don't you want to shine and make glad the innocent heart of a child, the striving heart of the young, the sorrowful and vexed heart of the middle-aged, and the weary heart of the old? Well did Robert Louis Stevenson say: A happy man or woman is a better thing to find than a five-pound note. He or she is a radiating focus of good will; and their entrance into a room is as though another candle had been lighted. There is no duty we so much underrate as the duty of being happy. By being happy, we sow anonymous benefits upon the world, which remain unknown even to ourselves, or when they are disclosed, surprise nobody so much as the benefactor. Make the most of your happiness, and the least of your sorrows. Use the telescope at the enlarging end for the former and at the reducing end for the latter, until you have learned what most of us have to _learn_--how foolish and wrong it is to make our joys mere _incidents_ while we make our sorrows _events_.