CIRCULATION OF THE BLOOD 89 



henceforth give constant signs of life. When at length, and 

 after the lapse of a few days, the outline of the body begins 

 to be distinguished, then is the ventricular part of the heart 

 also produced, but it continues for a time white and appar- 

 ently bloodless, like the rest of the animal; neither does it 

 pulsate or give signs of motion. I have seen a similar con- 

 dition of the heart in the human foetus about the beginning 

 of the third month, the heart then being whitish and blood- 

 less, although its auricles contained a considerable quantity 

 of purple blood. In the same way in the egg, when the chick 

 was formed and had increased in size, the heart too in- 

 creased and acquired ventricles, which then began to receive 

 and to transmit blood. 



And this leads me to remark that he who inquires very 

 particularly into this matter will not conclude that the 

 heart, as a whole, is the primum vivens, ultimum moriens, 

 the first part to live, the last to die, but rather its auricles, 

 or the part which corresponds to the auricles in serpents, 

 fishes, etc., which both lives before the heart and dies 

 after it. 



Nay, has not the blood itself or spirit an obscure palpita- 

 tion inherent in it, which it has even appeared to me to 

 retain after death? and it seems very questionable whether 

 or not we are to say that life begins with the palpitation or 

 beating of the heart. The seminal fluid of all animals the 

 prolific spirit, as Aristotle observed, leaves their body with 

 a bound and like a living thing; and nature in death, as 

 Aristotle 1 further remarks, retracing her steps, reverts to 

 where she had set out, and returns at the end of her course 

 to the goal whence she had started. As animal generation 

 proceeds from that which is not animal, entity from non- 

 entity, so, by :a retrograde course, entity, by corruption, is 

 resolved into nonentity, whence that in animals, which was 

 last created, fails first and that which was first, fails last. 



I have also observed that almost all animals have truly a 

 heart, not the larger creatures only, and those that have red 

 blood, but the smaller, and pale-blooded ones also, such as 

 slugs, snails, scallops, shrimps, crabs, crayfish, and many 

 others; nay, even in wasps, hornets, and flies, I have, with 

 De Motu Animal., cap. 8. 



