Luserne should be order’d for Hay in the same Manner as is directed for St. Foin in the foregoing Chapter: But it must be observ’d, that Luserne is more worsted by being suffer’d to survive its Virginity before cutting; and therefore the richest and most nourishing Hay is cut whilst the Stalks are single, without any collateral Branches shooting out of them; and when they are so, neither Blossoms nor even their Buds appear. But of that sown in the old Fashion, the last Crops, for want of a new Supply of Nourishment, grow so slowly, that ere it is high enough to be cut, the Blossoms are blown out, and the Stalks, tho’ very small, are become _woody, hard_, and _dry_, and make the Hay nothing near so nourishing as that of the first Crops. But in that which is ho’d, the last Crops of it will, by virtue of the greater Quantity of Nourishment it receives, grow faster, and be of an Height fit to cut before blossoming, and thence being as young and vigorous, make as good Hay as the first Crops; so that Hoeing does not only procure more and larger Crops, but also better Hay. This is most certain, that unless we can keep our Luserne pretty clean from natural Grass, we cannot expect it to succeed, let the Soil be never so proper. CHAP. XIV. _Of Change of_ SPECIES. I. _That Plants of the most different Nature feed on the same Sort of Food._ II. _That there is no Plant but what must rob any other Plant within its Reach._ III. _That a Soil which is proper to one Sort of Vegetable once, is, in Respect of the Sort of Food it gives, proper to it always._ If any one of these _Three Propositions_ be true, as I hope to prove all of them are, then it will follow, that there is no need to change the Species of _Vegetables_ from one Year to another, in respect to the different Food the same Soil is, tho’ falsely, supposed to yield[201]. [201] For if all Plants rob one another, it must be because they all feed on the same Sort of Food; and, admitting they do, there can be no Necessity of changing the Species of them, from one Soil to another; but the same Quantity of the same Food, with the same Heat and Moisture which maintains any Species one Year, must do it any other Year. The common Opinion is contrary to all these (as it must be, if contrary to any one of them): And since an Error in this fundamental Principle of _Vegetation_ is of very ill Consequence; and since Dr. _Woodward_, who has been serviceable in other respects[202] to this Art, has unhappily fallen in with the Vulgar in this Point; his Arguments for this Error require to be answer’d in the first Place. [202] By proving, in his Experiments, that Earth is the _Pabulum_ of Plants.