Therefore the crude Earth, being their Food, simple and free from any Alterations by Vessels, remaining insipid, cannot give, neither can Plants receive, require, or make use of, any Variety from it, as Animals do from their Diet. It would be lost upon them, and Nature would have acted in vain, to give Smell and Taste to Vegetables, and nothing but insipid Earth for an Object of them; or to give them a charming Variety of Relish and Savour in their Food, without giving them Senses necessary to perceive or enjoy them; which would be like Light and Colours to the Blind, Sound and Music to the Deaf, or like giving Eyes and Ears to Animals, without Light or Sound to affect them.
The Mouths of Plants, situate in the convex Superficies of Roots, are analogous to the Lacteals, or Mouths, in the concave Superficies of the Intestines of Animals.
These spongy Superficies of animal Guts, and vegetable Roots, have no more Taste or Power of refusing whatever comes in Contact with them, the one than the other.
The free open Air would be equally injurious to both; and if exposed to it, it would dry and close up the fine Orifices in Guts and Roots: Therefore Nature has guarded both from it.
Nature has also provided for the Preservation of both Vegetables and Animals (I do not say equally) in respect of their Food; which might poison them, or might not be fit to nourish them.
The Security of Plants (the best that can be) is their Food itself, Earth; which, having been altered by no Vessels, is always safe and nourishing to them; For a Plant is never known to be poisoned by its own natural Soil, nor starved, if it were enough of it, with the requisite Quantities of Heat and Moisture.
Roots, being therefore the Guts of Plants, have no need to be guarded by Senses; and all the Parts and Passages, which serve to distinguish and prepare the Food of Animals, before it reach the Guts, are omitted in Plants, and not at all necessary to them.
But as the Food of most Animals is Earth, very variously changed and modified by vegetable or animal Vessels, or by both, and some of it is made wholsome, some poisonous; so that if this doubtful Food should be committed to the Intestines, without Examination, as the pure unaltered Earth is to Roots, there would, in all Probability, be very few Animals living in the World, except there be any that feed on Earth at first Hand only, as Plants do.
Therefore, lest this Food, so much more refined than that of Plants, should, by that very means, become a fatal Curse, instead of a Blessing to Animals, Nature has endowed them with Smell and Taste, as Sentinels, without whose Scrutiny these various uncertain Ingredients are not admitted to come where they can enter the Lacteals, and to distinguish, at a sufficient Distance, what is wholsome and friendly, from what is hurtful; for when ’tis once passed out of the Stomach into the Guts, ’tis too late to have Benefit from Emetics; its Venom must then be imbibed by the Lacteal Mouths, and mix with the Blood, as that must mix with the Sap, which comes in Contact with the Lacteals in the Superficies of Roots, Nature having left this unguarded.
Yet Plants seem to be better secured by the Salubrity and Simplicity of their Food, than Animals are by their Senses: To compensate that Inequality of Danger; Animals have Pleasure from their Senses, except some miserable Animals (and such there are) that have more Pain than Pleasure from them. But I suppose, more Animals than Plants are poison’d; and that a poisonous Animal is less fatal to a Plant, than a poisonous Plant is to an Animal.