The painter who is familiar with the nature of the sinews, muscles, and tendons, will know very well, in giving movement to a limb, how many and which sinews cause it; and which muscle, by swelling, causes the contraction of that sinew; and which sinews, expanded into the thinnest cartilage, surround and support the said muscle.

The frog instantly dies when the spinal cord is pierced; and previous to this it lived without head without heart or any bowels or intestines orskin; and here therefore it would seem lies the foundation of move- ment and life.

Then you shall make a discourse on the hands of each animal in order to show how they vary, as in the bear in which the ligaments ofthe tendons of the toes of the foot are connected over the neck of the foot.

That cause which moves the water through its springs against the natural course of its gravity is like that which moves the humours in all the shapes of animated bodies.

The frog retains life for some hours when the head the heart and all the intestines have been taken away. And if you prick the said cord it instantly twitches and dies.

And this network of veins acts in man as in oranges, in which the peel becomes thicker and the pulp diminishes the more they become old. And if you say that as the blood becomes thicker it ceases to flow through the veins, this is not true, for the blood in the veins does not thicken because it continually dies and is renewed.