"But, as you know," said Percy, "milk is the only food of young animals, and they must secure their bone food from the milk. Furthermore, the complete analysis of milk shows that it contains very considerable quantities. There are also records of digestion experiments in which less than one-half of the phosphorus in the food consumed was recovered in the total manural excrements. As a matter of fact there is a time in the life of the young mother, as with the two-year old cow, for example, when she must abstract from the food she consumes sufficient phosphorus for the nourishment of three growing animals,--her own immature body, a suckling calf, and another calf as yet unborn. "Of course the organic matter of the soil should increase under pasturing, especially under conditions that make possible an accumulation of nitrogen; but here too the animals make no contribution toward any such accumulation. With the same growth of plants the accumulation of organic matter would be much more rapid without live stock." "It is known absolutely but not generally that live stock destroy about two-thirds of the organic matter contained in the food they consume. With grains the proportion is higher, and with coarse forage it is lower, but as an average about two-thirds of the dry matter in tender young grass or clover or in a mixed, well-balanced ration of grain and hay is digested and thus practically destroyed so far as the production of organic matter is concerned. "This you could easily verify yourself, Mr. West, by feeding two thousand pounds of any suitable ration, such as corn and clover hay, collecting and drying the total excrement, which will be found to weigh about seven hundred pounds, if it contains no higher percentage of moisture than was contained in the two thousand pounds of food consumed. "Of course one should not forget that the liquid excrement contains more nitrogen and more potassium than the solid, and that much of this can be saved and returned to the land by use of plenty of absorbent bedding, and in pasturing there is no danger of any loss from this source." "That is one great trouble with us," said Mr. West. "We never have as much bedding as we could use to advantage, and it is altogether too expensive to permit us to think of buying straw."