In the field of biology, the Yosemite forests attracted the first attention of scientists. Botanists generally agree that in the Big Tree, the sugar pine, the yellow pine (ponderosa and Jeffrey), the red and white firs, and the incense cedar of the Sierra is the finest and most remarkable group of conifers in the world. The Big Tree (_Sequoia gigantea_), of course, is the most phenomenal and claims first place, chronologically, in the scientific literature. In the number of workers concerned with it and in the quantity of their writings, the Big Tree also holds a respected place. Among the early writers who dealt with the Big Tree groves of the present Yosemite National Park were Hutchings, Whitney, Asa Gray, Isaac N. Bromley, J. Otis Williams, Muir, Bunnell, and Clark. The latter was among the first to study the Sequoia groves of the Yosemite but he did not publish for nearly half a century after he made his first observations. Following the early announcements of the existence of the Tuolumne, Merced, and Mariposa groves, another group of botanists and semiprofessional workers concentrated upon the study of the Big Tree. Walter G. Marshall, Charles Palache, Paul Shoup, Julius Starke, George Dollar, and W. R. Dudley made their contributions at this time, and Muir redoubled his initial efforts. After the turn of the century, botanists and foresters in numbers concentrated upon the Big Tree. Their publications are too numerous to list, but special mention must be made of the work of Willis L. Jepson, George B. Sudworth, Ellsworth Huntington, James C. Shirley, L. F. Cook, and the continued inspired writing of Muir. The sequoia, oldest living thing, is now and always will be a fascinating subject for scientific and philosophical study. Until a thorough investigation of the ecology of a grove of giant sequoias has been made and its result published, there remains a practical need for research in this realm.