HEART AND BLOOD. 29 



the third month, the heart being then whitish and bloodless, 

 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 increased and acquired 

 ventricles, which then began to receive and to transmit blood. 



And this leads me to remark, that he who inquires very par- 

 ticularly 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, &c., which both 

 lives before the heart 1 and dies after it. 



Nay, has not the blood itself or spirit an obscure palpitation 

 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 2 further re- 

 marks, retracing her steps, reverts to whence she*had set out, 

 returns at the end of her course to the goal whence she had 

 started; and 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 non-entity ; 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 [seemingly] bloodless ones also, 

 such as slugs, snails, scallops, shrimps, crabs, crayfish, and 

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

 with the aid of a magnifying glass, and at the upper part of 

 what is called the tail, both seen the heart pulsating myself, 

 and shown it to many others. 



But in the exsanguine tribes the heart pulsates slugglishly 

 and deliberately, contracting slowly as in animals that are mo- 

 ribund, a fact that may readily be seen in the snail, whose 



1 [The reader will observe that Harvey, when he speaks of the heart, always means 

 the ventricles or ventricular portion of the organ. ED.] 

 a De Motu Animal, cap. 8. 



