372. CHAPTER V. THE HEART OF THE TURTLE.
THE use of the foramen ovals and ductus arteriosus, is shown by the heart of the turtle more clearly than by any other. For in this animal there are two large arteries, one of which resembles the ductus arteriosus; and two foramina, one of which resembles the foremen ovale of embryos, which foramina are opened and shut according as the animal is in the water or in the air. To make the subject clear, then, I will add a brief chapter on the heart of the turtle.
