AN ANATOMICAL STUDY ON THE 



they are present in the left, none are found in the 

 right chamber. In man there are more in the left 

 than in the right ventricle, and more in the ventricles 

 than in the auricles, and in some subjects it seems 

 there are none in the auricles. In large, muscular, 

 peasant-type individuals there are many, in more 

 slender frames, and in women, few. 



In some animals the ventricles of the heart are 

 smooth inside, entirely without fibers or bands. 

 In almost all small birds, serpents, frogs, turtles, 

 and such like, and in most all fishes, neither fibers, 

 or so-called nerves, nor tricuspid valves are found 

 in the ventricles. 



In some animals the right ventricle is smooth 

 inside while the left has these fibrous bands, as in 

 the goose, swan, and heavier birds. The reason is 

 the same here as elsewhere. Since the lungs are 

 spongy, loose, and soft, not so great a force is needed 

 to pump blood through them. Therefore the right 

 ventricle either has none of these fibers or they are 

 few and weak, not fleshy or muscular. Those of the 

 left ventricle, however, are stronger, more numerous, 

 and more muscular because this chamber needs 

 to be more powerful since it must propel blood 

 farther through the whole body. This is also why 

 the left ventricle is placed in the middle of the 

 heart, and has walls three times as thick and strong 

 as the right. 



So all animals, man included, that have a stronger 

 and more sturdy frame, with large, brawny limbs 



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