In the succeeding chapters Harvey continues his observations on phlebotomy, and draws a conclusion so striking in its simplicity that it appears hard to understand why it had not already occurred to others. He says: "And now, too, we understand why in phlebotomy we apply one ligature above the part that is punctured, not below it: did the flow come from above, the constriction in this case would not only be of no service but would prove a positive hindrance. It would have to be applied below the orifice in order to have the flow more free did the blood descend by the veins from the superior to inferior parts." Harvey next returns to the question whether the blood does or does not flow in a continuous stream through the heart--a subject upon which his contemporaries had the wildest notions, for even Cesalpino says: "That whilst we are awake there is a great afflux of blood and spirit to the arteries whence the passage is to the nerves and whilst we are asleep the same heat returns to the heart by the veins, not by the arteries, for the natural ingress to the heart is by the _vena cava_, not by the artery ... so that the undulating flow of blood to the superior parts, and its ebb to the inferior parts--like Euripus--is manifest in sleeping and waking." Harvey combats this theory in exactly the same manner as we should do if it were propounded at the present day. He first brings forth his mathematical proof of the circulation, and then continues his surgical observations upon the operation of bleeding. "It is still further to be observed that in practising phlebotomy the truths contended for are sometimes confirmed in another way, for having tied up the arm properly and made the puncture duly, still, if from alarm or any other causes, a state of faintness supervenes, in which the heart always pulsates more languidly, the blood does not flow freely, but distils by drops only. The reason is that with the somewhat greater than usual resistance offered to the transit of the blood by the bandage, coupled with the weaker action of the heart and its diminished impelling power, the stream cannot make its way under the ligature; and further, owing to the weak and languishing state of the heart, the blood is not transferred in such quantity from the veins to the arteries through the sinuses of that organ.... And now a contrary state of things occurring, the patient getting rid of his fear and recovering his courage, the pulse strength is increased, the arteries begin again to beat with greater force, and to drive the blood even into the part that is bound, so that the blood now springs from the puncture in the vein, and flows in a continuous stream...." Thus far, he proceeds, "we have spoken of the quantity of blood passing through the heart and the lungs in the centre of the body, and in like manner from the arteries into the veins in the peripheral parts, and in the body at large. We have yet to explain, however, in what manner