From his early boyhood days in Switzerland, Louis Agassiz probed the secrets of natural science. Always exploring and adding to his diversified collections, Louis' future work began to take shape. His studies in Munich and Paris and with the famous Baron von Humboldt, proved invaluable. Summers spent in the Alps inspired an investigation of the ice age and made possible his ascent of the Jungfrau. In America Agassiz was instrumental in setting up a museum of natural science and in opening many pairs of hungry eyes to the world of nature. This learned, enthusiastic account with illustrations by Rafaello Busoni will please the young naturalist or zoologist of today primarily because of its concern with Agassiz the scientist. For those interested in rounding out the portrait of Agassiz, the man, we recommend for supplementary reading, Adventurous Alliance, a biography written for adults by this same skillful author.