The Principles of Biology, Nide 1

actions adaptation aggregate allied alterations Amphibia arise arrangement assimilation atoms axis become birds body carbonic acid cause cells centres changes chemical classes colloids combinations complex compounds constituting continuous contrasts creatures crustaceans Darwin definite degree differentiation distinct divergence effects embryo environment ethereal waves evidence exist external facts Faunas fertilized germ flower functions further gamogenesis genesis geologic greater groups growth habitats habitually Hence heterogeneity higher homogeneous Hydrozoa hypothesis of evolution implies incident forces increase individuals kind larvæ less living mammals manifest mass ment modes modifications molecular mobility moving equilibrium multiplication natural selection nitrogenous nutriment nutrition offspring organic forms organic matter oviparous ovules ovum parent parthenogenesis peculiarities phenomena physiological units pistil produced Protozoa races re-actions re-distribution relations reproductive result similarly special creations species sperm-cells and germ-cells stamens structure substances successive tion tissues truth types undergo unlike variations vertebral vertebral column Vertebrata viviparous