Since the eye is a bud and our potato plant for next year is to develop from this bud, it is of much importance, as we have seen, to know exactly what _kind_ of plant our potato comes from. If the potato is taken from a small plant that had but a few poor potatoes in the hill, we may expect the bud to produce a similar plant and a correspondingly poor crop. We must see to it, then, that our seed potatoes are drawn from vines that were good producers, because new potato plants are like the plants from which they were grown. Of course when our potatoes are in the bin we cannot tell from what kind of plants they came. We must therefore _select our seed potatoes in the field_. Seed potatoes should always be selected from those hills that produce most bountifully. Be assured that the increased yield will richly repay this care in selecting. It matters not so much whether the seed potato be large or small; it must, however, come from a hill bearing a large yield of fine potatoes. [Illustration: FIG. 46. BEGONIA-LEAF CUTTING] Sweet-potato plants are produced from shoots, or growing buds, taken from the potato itself, so that in their case too the piece that we use in propagating is a part of the original plant, and will therefore be like it under similar conditions. Just as with the Irish potato, it is important to know how good a yielder you are planting. You should watch during harvest and select for propagation for the next year only such plants as yield best. We should exercise fully as much care in selecting proper individuals from which to make a cutting or a layer as we do in selecting a proper animal to breed from. Just as we select the finest Jersey in the herd for breeding purposes, so we should choose first the variety of plant we desire and then the finest individual plant of that variety. If the variety of the potato that we desire to raise be Early Rose, it is not enough to select _any_ Early Rose plants, but the very best Early Rose plants, to furnish our seed. [Illustration: FIG. 47. LAYERING] It is not enough to select large, fine potatoes for cuttings. A large potato may not produce a bountifully yielding plant. _It will produce a plant like the one that produced it._ It may be that this one large potato was the only one produced by the original plant. If so, the plant that grows from it will tend to be similarly unproductive. Thus you see the importance of _selecting in the field a plant that has exactly the qualities desired in the new plant_.