8 LIST OF ILLUSTRATIONS. 



FACE 



CUP SPONGE, HALF THE NATURAL SIZE ... ... ... 194 



INTERIOR OF SPONGE CHANNELS ... ... ... ... 196 



ENLARGED POLYPES OF BED CORAL ... ... ... ... 197 



VARIOUS FORMS OF SPONGE SPICULES ... ... ... 199 



ANCHORS AND PLATES OF SYNAPTA ... ... ... ... 200 



A GROUP OF SPONGES ... ... ... ... ... 202 



EXPULSION OF WATER BY A LIVING SPONGE ... ... ... 203 



VERTICAL SECTION OF HUMAN SKIN ... ... ... 216 



AIR-CELLS OF HUMAN LUNG ... ... ... ... ... 218 



VOLUNTARY MUSCLE WITH TRICHINA ... ... ... 221 



POND-LlFE, HIGHLY MAGNIFIED ... ... ... ... 228 



GROUP OF VORTICELLJE ... ... ... ... ... 231 



STAR-FISHES ... ... ... ... " ... ... 238 



TRANSVERSE SECTION OF ECHINUS SPINE ... ... ... 238 



A FAMILY OF CORALS ... ... ... ... ... 239 



COMMON SPONGE, SHOWING THE OSCULA ... ... ... 240 



SERTULARIA: A MARINE ZOOPHYTE ... ... ... ... 242 



SILICEOUS CUTICLE or WHEAT STRAW ... ... ... 252 



SMUT ON MAIZE ... ... ... ... ... ... 254 



THE EFFECT OF POLARIZED LIGHT UPON MINERAL SUBSTANCE 259 



PALATE OF SEA-SNAIL (TROCHUS) ... ... ... ... 262 



PALATE OF SEA-SLUG (DORIS) ... ... ... ... 263 



A PORTION OF THE TEETH OF GARDEN SNAIL ... , ... ... 263 



GARDEN SNAIL ... ... ... ... ... ... 264 



A PALM GBOVE ... ... ... ... ... , 286 



