AN ANATOMICAL STUDY ON THE 



which blood may forcibly pour, but that nothing 

 like this happens in the intact body, with no out- 

 let made. With the arteries filled, in their natural 

 state, so large an amount cannot pass in so short 

 a time as to make a return necessary. It may be 

 replied that from the computation and reasons 

 already given, the excess contained in the dilated 

 heart in comparison with the constricted must 

 be in general pumped out with each beat and this 

 amount must be transmitted, as long as the body 

 is intact and in a natural state. 



In serpents and certain fishes by ligating the 

 veins a little below the heart, you will see the space 

 between the ligature and the heart quickly become 

 empty. So, unless you deny what you see, you must 

 admit the blood returns to the heart. This will 

 be clear later in discussing the second proposition. 



We may close here with a single conclusive ex- 

 ample, by which anyone may be convinced by his 

 own eyes. 



If a live snake be cut open, the heart may be 

 seen quietly and distinctly beating for more than 

 an hour, moving like a worm and propelling blood 

 when it contracts longitudinally, for it is oblong. 

 It becomes pale in systole, the reverse in diastole, 

 and almost all the other things we have mentioned 

 as proving the truth may be clearly observed, for 

 here all happens slower and more distinctly. This 

 especially may be seen more clearly than the midday 

 sun. The vena cava enters at the lower part of the 



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