LIST OF ILLUSTRATIONS. 



SCALE FROM POLYOMMATUS ARGUS ... ... ... ... 54 



VARIOUS FORMS OP SCALES OF BUTTERFLIES ... ... 54 



SECRETING ORGANS OF A CATERPILLAR ... ... ... 56 



THE PEACOCK BUTTERFLY ... ... ... ... 57 



THE CONVOLVULUS SPHINX ... ... ... ... ... 60 



A FAMILY VISIT ... ... ... ... ... 62 



PROBOSCIS OF BUTTERFLY ... ... ... ... ... 63 



DIFFERENT FORMS OF BUTTERFLIES' TONGUES ... ... 65 



SECTION OF PROBOSCIS OF A MOTH ... ... ... ... 67 



EGG-BOAT OF THE COMMON GNAT... ... ... ... 70 



LARVA AND PUPA OF COMMON GNAT ... ... ... ... 71 



TRANSITION: BURIED PUPA OF A HAWK MOTH ... ... 73 



LOCUST ... ... ... ... ... ... ... 77 



HEAD OF SPIDER ... ... ... ... ... 100 



BRUSH AND COMBS OF CELLAR SPIDER ... ... ... 107 



GARDEN SPIDER'S WEB ... ... ... ... ... 110 



SPINNERET OF SPIDER ... ... ... ... ... 112 



VISCID AND ORDINARY THREADS OF SPIDER ... ... 117 



FERN, WITH FRUCTIFICATION ... ... ... ... ... 129 



MOUTH OF THE CAPSULE OF A Moss ... ... ... 131 



DIATOMS, SHOWN WITH DARK-GROUND ILLUMINATION ... ... 143 



TRANSVERSE SECTION OF A NEW ZEALAND PLANT ... ... 148 



PORTION OF LEAF, SHOWING CELLULAR TISSUE AND STOMATA ... 150 



SKELETON OF BLACK POPLAR LEAF ... ... ... 151 



SILICEOUS SKELETON OF DEUTZIA ... ... ... ... 153 



SECTION OF OAK, EIGHTEEN YEARS' GROWTH ... ... 158 



STAMENS, WITH POLLEN, OF MALLOW ... ... ... ... 161 



FECUNDATION OF SUNFLOWER ... ... ... ... 163 



CIRCULATION IN A LEAF ... ... ... ... ... 165 



CELLS FROM THE PETAL OF GERANIUM ... ... ... 167 



TRANSVERSE SECTION OF TOOTH OF MYLIOBATES ... ... 168 



TRANSVERSE SECTION OF CHERRY-STONE ... ... ... 173 



SECTION OF CHALK, WITH FOSSILS IN SITU ... ... ... 181 



SECTION OF LIMESTONE ... ... ... ... ... 182 



FORAMINIFERA, FROM SPONGE OF COMMERCE ... ... ... 184 



FORAMINIFEB, WITH EXTENDED PSEUDOPODIA ... ... 185 



FOSSIL DIATOMACILB ... ... ... 189 



