defined, with its indispensability in countries in which the water for the sheep has to be drawn from deep [159] wells, or in which the flock has to be defended from wolves or from human depredators. As to land, it has been shown that, except as affording mere room and standing ground, the importance of land, great as it may be, is secondary. The one thing needful for economic production is the green plant, as the sole producer of vital capital from natural inorganic bodies. Men might exist without labour (in the ordinary sense) and without land; without plants they must inevitably perish. * In some remarkable passages of the Botany of Sir James Ross's Antarctic voyage, which took place half a century ago, Sir Joseph Hooker demonstrated the dependence of the animal life of the sea upon the minute, indeed microscopic, plants which float in it: a marvellous example of what may be done by water-culture. One might indulge in dreams of cultivating and improving diatoms, until the domesticated bore the same relation to the wild forms, as cauliflowers to the primitive Brassica oleracea, without passing beyond the limits of fair scientific speculation. That which is true of the purely pastoral condition is a fortiori true of the purely agricultural* condition, in which the existence of the cultivator is directly dependent on the production of vital capital by the plants which he cultivates. Here, again, the condition precedent of the work of each year is vital capital. Suppose that a man lives exclusively upon the plants which he cultivates. It is obvious that he must have food-stuffs to live upon, while he prepares the soil for sowing and throughout the period which elapses between this and harvest. These food-stuffs must be yielded by the stock remaining over from former crops. The result is the same as before--the pre-existence of vital capital is the necessary antecedent of labour. Moreover, the amount of labour which contributes, as an accessory condition, to the production [160] of the crop varies as widely in the case of plant-raising as in that of cattle-raising. With favourable soil, climate and other conditions, it may be very small, with unfavourable, very great, for the same revenue or yield of food-stuffs. * It is a pity that we have no word that signifies plant-culture exclusively. But for the present purpose I may restrict agriculture to that sense.