The illustrations in the book require a word of credit. The eleven color plates of adult butterflies with wings spread have been made direct from a set of the remarkable transfers which Mr. Sherman F. Denton has been preparing for the last quarter-century, this particular set having been prepared especially for this book. Transfers of this sort were used as insets in Mr. Denton's work on the "Moths and Butterflies of the United States," published in a limited edition by J. B. Millet Company, Boston. The other plates not reproduced from photographs are from drawings by Miss Mary E. Walker or Mr. W. I. Beecroft. In case the photographs are not of my own taking, credit is given beneath each. Two of my photographs have already appeared in "Seeing Nature First" and are here used by permission of its publishers, J. B. Lippincott Company. C. M. W. STATE NORMAL SCHOOL, Lowell, Mass. CONTENTS PAGE PREFACE v LIST OF COLORED ILLUSTRATIONS xi LIST OF OTHER ILLUSTRATIONS xiii PART I INTRODUCTION BUTTERFLY TRANSFORMATIONS 5 BUTTERFLIES AND MOTHS 13 THE SCENTS OF BUTTERFLIES 15 BUTTERFLY MIGRATIONS 16 HIBERNATION OR WINTER LETHARGY 17 AESTIVATION OR SUMMER LETHARGY 21 FEIGNING DEATH IN BUTTERFLIES 22 COLORATION OF BUTTERFLIES 24 SELECTIVE COLOR SENSE IN BUTTERFLIES 32 WARNING COLORATION AND MIMICRY 33 HELIOTROPISM IN BUTTERFLIES 35 PARASITIC ENEMIES OF BUTTERFLIES 40 REARING BUTTERFLIES FROM CATERPILLARS 43 PHOTOGRAPHING BUTTERFLIES 47 BUTTERFLY COLLECTIONS 49 PART II