Fertilization of flowering plants -- Relation of pollen to the seed vessels -- Need for transference of pollen -- Means to prevent self-fertilization -- Relation between animal life and vegetable -- Search for honey by bees and other insects -- Bearing the pollen to distant flowers -- Distribution of work among insects and birds -- Evidence of adaptation -- Interdependence of lower and higher organisms -- ANTS -- Their exclusion from certain flowers -- Their work, perseverance, intelligence, slave-holding, extracting honey from other insects, constructing bridges 162 LECTURE VI. HIGHER ORGANISMS; -- RESEMBLANCES AND CONTRASTS. Sensibility and motor activity characteristic of animal life -- Both uniformly provided for by identical arrangements of nerve system -- Two distinct lines of nerve fibre combined in a nerve centre -- Structure of nerve fibre -- Isolation -- Combination -- Brain structure -- White matter, and grey -- Subdivisions of the organ -- Complexity of brain structure according to complexity of organism -- Brain in insects, fishes, reptiles, smaller quadrupeds, larger quadrupeds, monkeys, apes, man -- Close resemblance of the brain of the ape to the human brain -- Researches as to brain function by means of electric excitation of the organ -- Fritsch and Hitzig -- Ferrier -- Identification of sensory and of motor centres -- Silence of front and back regions -- Confirmatory evidence from brain diseases 204 LECTURE VII. MAN'S PLACE IN THE WORLD. Human organism modelled on the same plan as lower organisms -- Prevailing opinion opposes an attempt to refer all human activity to organism -- Religious thought not directly involved -- Science must include the study of human life -- Science by discovery of the structure and functions of the nerve system has explained many phases of action formerly regarded as voluntary -- The contrast remains between muscular action and human conduct -- Acquired aptitudes -- Intellectual superiority -- Hæckel's suggestion of "mind cells" -- Adverse evidence -- Nerve cells, varied sizes, the largest found in the spinal canal, as well as in the brain -- Government of human conduct -- Man's application of a higher law -- Benevolence, as an illustration -- Contrast with struggle for existence -- Man's ideal law, constituting the _ought_ in human conduct 239 LECTURE VIII. DIVINE INTERPOSITION FOR MORAL GOVERNMENT.