OF THE MEANS OF ACQUIRING UNIVERSALITY.
It is an easy matter to men to acquire universality, for all terrestrial animals resemble each other as to their limbs, that is in their muscles, sinews and bones; and they do not vary excepting in length or in thickness, as will be shown under Anatomy. But then there are aquatic animals which are of great variety; I will not try to convince the painter that there is any rule for them for they are of infinite variety, and so is the insect tribe.
Taken from The Notebooks of Leonardo da Vinci edited by Jean Paul Richter, 1880.