AND PERSONALITY 



same weight, as the ratios express the energy characteristics 

 of each. 



We see in the following table a striking preponderance of 

 brain in the shark as compared with the weight of the brain 

 in the jewfish as striking as the difference in the behavior 

 characteristics of these two animals. 



The green turtle of the sea is protected by a complete 

 and efficient armor into which it can withdraw its neck and 

 head and feet. Much of the food on which the turtle lives 

 floats to it. 



The great advantage that the turtle has over the shark 

 and the jewfish is that the turtle has lungs and breathes air 

 that has a high concentration of oxygen. When the lungs 

 hence the blood is well saturated with oxygen, the turtle 

 has greater power than a fish that has to depend on the 

 attenuated oxygen in the water. The muscles of the turtle, 

 therefore, exhibit a greater capillary circulation than the 

 muscles of a fish. 



The large heart and the large volume of blood in the 

 turtle are an adaptation not for muscle power or for the 

 maintenance of the warm-blooded state but for providing 

 stores of oxygen to sustain the turtle while he is submerged 

 in search of food. This point is supported by the following 

 evidence: A turtle weighing 150 pounds had a brain weigh- 

 ing 5.81 grams, whereas a sand shark weighing 79 pounds 

 had a brain weighing 50.03 grams. 



Though unlimited oxygen is available to it, the reptile 

 has been evolved toward a minimum use of oxygen. Com- 

 peting against other reptiles and against the warm-blooded 



