The Structure and Function of Roots

Abstract

In the latter part of the 17th century, Robert Hooke was one of the most influential scientists in the world. This versatile genius, who was adept in all areas of science known at that time, was Curator of Experiments, and also for a time served as Secretary, to the Royal Society in London. Among his many duties he was required, on occasion, to comment on the scientific papers presented by members at the weekly meetings of the Society. One such paper described studies of the translocation of substances within trees. It contained some interesting experiments and observations, but it was not a particularly distinguished investigation. Hooke’s comments following the presentation, however, are, when seen with the perspective of time, truly remarkable. He said:

“To me it seems very probable, that the bodies of plants, as well as those of moving animals, are nourished and increased by a double food, the one an impregnated water, and the other an impregnated air, and that without a convenient supply of these two, the vegetable cannot subsist, at least not increase; these do mutually mix, and coalesce, and parts of the air convert to water, and parts of water to air, as some of these latter are rarify’d and freed from their chains, and become spiritual and airy, so others of the forementioned are clogged, and fettered and become debased. To this purpose all plants, as well as animals, have a two-fold kind of root, one that branches, and spreads into the earth, and other that spreads and shoots into the air, both kinds of roots serve to receive and carry their proper nourishment to the body of the plant, and both serve also to convey and carry off the useless recrements; useless I mean any farther, within the body of the plant, though useful to it when they are separated, and without it, the one for seasoning the earth and water, wherein it is planted, and the other for seasoning the air.”