And Philo subjoined: There is, Crato, a reason for this amongst the philosophers, which the gardeners confirm and strengthen. For they say, oil is very hurtful to all plants, and any plant dipped in it, like a bee, will soon die. Now these trees are of a fat and oily nature, insomuch that they weep pitch and rosin; and, if you cut them gore (as it were) appears presently in the wound. Besides, a torch made of them sends forth an oily smoke, and the brightness of the flame shows it to be fat; and upon this account these trees are as great enemies to all other kinds of grafts as oil itself. To this Crato added, that the bark was a partial cause; for that, being rare and dry, could not afford either convenient room or sufficient nourishment to the grafts; but when the bark is moist, it quickly joins with those grafts that are let into the body of the tree.