the first stages of the domestication of cattle, it was possible to gain only a small supply of milk, since its over-production could be developed but slowly; just for this reason, however, milk was all the more valuable. This may probably also throw light on the high value which was long placed on butter as a sacrificial gift. The attempt to secure this valuable product for sacrificial purposes may then itself in turn have reacted upon the milk industry. Thus, the two great advances in material culture that attend the heroic age--the tilling of the soil with the plough and the systematic endeavour to secure milk and its products--seem to be, in part, directly due to, and, in part, closely bound up with, motives of cult. External culture and inner religious impulses have always attested themselves to be elements of a totality all of whose parts are interrelated. Of the new forms of industry which thus arose, the cultivation of the soil by means of the plough led to a further important change. This change was just as much an effect of the new conditions of life as it was an expression of the altered spirit of the times. The guidance of the plough is a task which prevents the field work from being any longer done in common, as it was at the height of hoe-culture and during the time of the origin of the great vegetation festivals of totemism. The individual must guide his own plough. The appearance of plough-culture _individualizes labour_. Just as the individual comes to the fore in political development and is extolled in legend as the founder of cities and States, so also is it the individual who cultivates the land. This individualistic tendency also gradually makes itself felt in the raising of domestic animals. Plough-culture gives rise to _private property_ as regards both the soil and its products.