XC. Creatures whose blood is copious and thick are hot-tempered. The blood of males is darker than that of females, and that of youth than that of old age; and it is thicker in the lower part of the body. The blood also contains a large proportion of vitality, and when shed it draws the breath with it; but it has no sense of touch. The animals with denser blood are braver, those with thinner blood wiser, and those with very little blood, or none at all, more timid. The blood of bulls coagulates and hardens most quickly (and consequently is noxious to drink); that of boars next quickly, but that of stags and goats and antelopes does not thicken at all. Asses have the thickest blood and man the thinnest. Species with more than four feet have no blood. Fat animals have a smaller supply of blood, because it is used up in the fat. In the human race alone a flux of blood occurs in the males, in some eases at one of the nostrils, in others at both, with some people through the lower organs, with many through the mouth; it may occur at a fixed period, as recently with a man of praetorian rank named Macrinus Viscus, and every year with the City Prefect Volusius Saturninus, who actually lived to be over 90. This alone of the bodily affections experiences an occasional increase, inasmuch as sacrificial victims bleed more copiously if they have previously drunk. XCI. Those animals which we have specified as going into hiding at fixed seasons have not any blood at those periods except quite scanty drops in the neighbourhood of the head, by a marvellous contrivance of nature, just as in man she causes the blood-supply to alter at the smallest impulses, the blood not only being suffused with less matter by sleep but at each separate state of mind, by shame, anger, and fear, there being various ways of turning pale, and also of blushingas the blush of anger is different from that of modesty. For it is certain that in fear the blood retreats and is nowhere to be found, and that many creatures do not shed blood when stabbed, which happens only to a human being. For those which we have spoken of as changing their colour really assume the colour of some other object by a sort of reflexion; only man actually changes colour in himself. All diseases and death reduce the amount of blood.