OUR ANCIENT RELATIVES 



In the brain these olfactory messages stimulate 

 the motor nerves controlling the eye muscles and 

 other nerves controlling the locomotor muscles, in 

 such a way that the shark turns and moves 

 toward the source of the odor. 



The eyes of a shark are fundamentally similar 

 to those of a man but their marvelous intricacy 

 forbids an attempt to discuss them in this brief 

 space. Each eye is moved by six sets of eye 

 muscles (Fig. 6), which turn the pupil toward the 

 goal of movement. 



As the food is reached and the stimulation of 

 smell, sight and other senses reaches its climax, 

 there is a convulsive expansion of the jaws, the 

 food is torn by the jagged teeth, the jaws snap shut 

 with the vicious force of a bear-trap, and the 

 intense pleasure of swallowing the precious life- 

 giving morsel is experienced. 



Thoroughly equipped research laboratories could 



profitably occupy the time for decades to come 



with a study of what really happens when a shark 



detects its food and rushes forward to engulf it, 



for this apparently simple but in reality vastly 



complex sequence holds many secrets of vital 



importance to human beings. 



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