XI.—Adult-Form of the same Six Crab Fish ” ” ” XII.—Ascidia and Amphioxus ” 201, 202 XIII.—Ascidia and Amphioxus ” ” ” XIV.—Single, or Monophyletic, Pedigree of Back-boned Animals _To face page_ 222 FIGURES. 8.—Protamœba Primitiva 52 9.—Bathybius Hæckelii 53 10.—Amœba Sphærococcus 54 11.—Euglena Striata 57 12.—Magosphæra Planula 58 13.—Labyrinthula Macrocystis 59 14.—Navicula Hippocampus 60 15.—Physarum Albipes 61 16.—Cyrtidosphæra Echinoides 66 17.—Caulerpa Denticulata 87 18.—Euastrum Rota 88 19.—Fucus Vesiculosus (egg of) 90 THE HISTORY OF CREATION. CHAPTER XV. PERIODS OF CREATION AND RECORDS OF CREATION. Reform of Systems by the Theory of Descent.—The Natural System as a Pedigree.—Palæontological Records of the Pedigree.—Petrifactions as Records of Creation.—Deposits of the Neptunic Strata and the Enclosure of Organic Remains.—Division of the Organic History of the Earth into Five Main Periods: Period of the Tangle Forests, Fern Forests, Pine Forests, Foliaceous Forests, and of Cultivation.—The Series of Neptunic Strata.—Immeasurable Duration of the Periods which have elapsed during their Formation.—Deposits of Strata only during the Sinking, not during the Elevation of the Ground.—Other Gaps in the Records of Creation.—Metamorphic Condition of the most Ancient Neptunic Strata.—Small Extent of Palæontological Experience.—Small proportion of Organisms and of Parts of Organisms Capable of Petrifying.—Rarity of many Petrified Species.—Want of Fossilised Intermediate Forms.—Records of the Creation in Ontogeny and in Comparative Anatomy.