Note 881 — Chapter V · (continued 3)

‘The variety of motions is greater in animals, and more purposes are answered by them.’ … ‘The first kind of action appears to be stronger in its power, although less in quantity, in vegetables than in animals; for a small vine was capable of sustaining, and even of raising, a column of sap 43 feet high, while a horse's heart was only capable of supporting a column of blood 8 feet 9 inches high; both of which columns must have been supported by the action of the internal parts, for we must suppose the heart equal, or nearly so, to the strength or action of the other parts of the vascular system; and when we consider that the sap of the tallest tree must be supported, and even raised from the root to the most distant branches, it must appear that the power of such vegetables far exceeds the power of any animal, and, indeed, it is such as the texture of a vegetable only can support. The power of supporting a leaf erect for a whole day is as great an effort of action as that of the elevator palpebrarum muscle of the eye of an animal.’ Hunter's Works, vol. iv. pp. 203, 204. See also Hunter's Essays, vol. i. p. 342: ‘It is probable that the vegetable which can the least bear a suspension of its actions, can do so more than the animal which can bear it longest.’