These remarks concerning end and means, and the pleasure accompanying use of the means as added to the pleasure derived from the end, I have made for the purpose of drawing attention to a fact of profound significance. During evolution there has been a superposing of new and more complex sets of means upon older and simpler sets of means, and a superposing of the pleasures accompanying the uses of these successive sets of means, with the result that each of these pleasures has itself eventually become an end. We begin with a simple animal which, without ancillary appliances, swallows such food as accident brings in its way; and so, as we may assume, stills some kind of craving. Here we have the primary end of nutrition with its accompanying satisfaction, in their simple forms. We pass to higher types having jaws for seizing and biting--jaws which thus, by their actions, facilitate achievement of the primary end. On observing animals furnished with these organs, we get evidence that the use of them becomes in itself pleasurable irrespective of the end: instance a squirrel which, apart from food to be so obtained, delights in nibbling everything it gets hold of. Turning from jaws to limbs we see that these, serving some creatures for pursuit and others for escape, similarly yield gratification by their exercise; as in lambs which skip and horses which prance. How the combined use of limbs and jaws, originally subserving the satisfaction of appetite, grows to be in itself pleasurable, is daily illustrated in the playing of dogs. For that throwing down and worrying which, when prey is caught, precedes eating, is, in their mimic fights, carried by each as far as he dares. Coming to means still more remote from the end, namely, those by which creatures chased are caught, we are again shown by dogs that when no creature is caught there is still a gratification in the act of catching. The eagerness with which a dog runs after stones, or dances and barks in anticipation of jumping into the water after a stick, proves that apart from the satisfaction of appetite, and apart even from the satisfaction of killing prey, there is a satisfaction in the successful pursuit of a moving object. Throughout, then, we see that the pleasure attendant on the use of means to achieve an end, itself becomes an end. Now if we contemplate these as phenomena of conduct in general, some facts worthy of note may be discerned--facts which, if we appreciate their significance, will aid us in developing our ethical conceptions. One of them is that among the successive sets of means, the later are the more remote from the primary end; are, as co-ordinating earlier and simpler means, the more complex; and are accompanied by feelings which are more representative.