AN ANATOMICAL STUDY ON THE 



ing to its real condition.^ All local motion in an 

 animal first takes place from the contraction of some 

 particular part. Thus blood is cast into the ventricles 

 by auricular contraction, as shown before, and then 

 passed on and distributed by the ventricular con- 

 traction. 



I have been interested in getting at the truth of 

 this matter of local motion. How the initial moti- 

 vating organ in all animals having a prime motive 

 spirit is, as Aristotle says in his book De Spiritu, 

 contractile; how vevpov is derived from vevo} {nuto^ 

 contraho)^ and how Aristotle had more than a super- 

 ficial acquaintance with muscles, and on that account 

 referred all motion in animals to nerves and a con- 

 tractile part, and hence called those bands in the 

 heart nerves, — all this I hope to make clear soon, if 

 I am permitted to demonstrate my observations on 

 the organic motion of animals and the structure of 

 muscles.^" 



^ According to present physiological conceptions, venous pressure 

 is great enough to open the auriculo-ventricular valves during dias- 

 tole, so that considerable blood flows into the ventricles while they are 

 relaxed and before the auricles start to contract. It is generally 

 agreed with Harvey that the ventricles have no suction power, but 

 it is felt that the contractions of the auricles force in only a portion 

 of the ventricular contents. See Note 4, Chapter IV. 



^" This treatise also disappeared. The derivation of terms is 

 apparently oflfered in apology for Aristotle's calling the muscular 

 bands in the heart "nerves." G. A. Borelli (1608-1679), in develop- 

 ing a mechanical analysis of muscular motion carried over a theory 

 of contraction caused by a liquid discharge from nerves {De motu 

 animalium, 1680). For a superb discussion of the physiology of muscle 

 consult J. F. Fulton's monograph, Baltimore, 1927. 



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