Consequently there is little that should provoke surprise on our part in the fact that not one man in (say) ten thousand is consciously puzzled by any of the deeper problems of life, not one in (say) a hundred thousand has his imagination either stirred or stunned by the green blades of the corn, the leaves of the tree, the grass in his fields or the sheep and cows that are eating it. There is nothing new about all this, nothing strange; it is familiar—therefore it is understood or there is nothing that calls for understanding. Yet in these green blades and leaves is the junction-point between the living and the not-living, between the plant and animal on the one hand and what we call 'inert matter' on the other, between the radiant energy of the sun and ourselves. And we do not understand, nobody understands, how that junction-point works. It is called chlorophyll; it is found in little living bodies called chloroplasts; and it is wonderful 'beyond all whooping'. Yet we do not even whoop. We do not get even thus far. We are not surprised, we are not enraptured. The thing is at once both too familiar and too obscure for us. We cannot do away with the familiarity; but at least, as reasonable beings possessed of that passion of desire which is a cry of the spirit within us and which we so often do our utmost to suppress, it will be well for us to make an attempt to find out how and even why this green stuff of the plant is so highly distinguished among the wonders of the world. But first let us ask ourselves a searching and pertinent question—let us ask ourselves what it means to be alive. A man is alive, but so are the cells of his own blood, so is the grass in the fields, so are the small jellies we call amoebae and the still smaller rods and specks we call bacteria and 'germs.' Can we say anything about life that will at once fit these and distinguish them from all else that does not live, accepting for the moment the distinction between living and not-living that we ordinarily make?