REPTILES 175 



portion of the plastron or undershell. This undershell 

 is relatively soft and elastic and being nearly flat the weight 

 of the animal resting upon it when stranded will, if con- 

 tinued for long, lead to impediment of breathing and 

 circulation. " Turned Turtles," therefore though ren- 

 dered helpless, stand a better chance of life in transit. 



GP 1 

 Green Turtles 



By sudden expulsion of the breath stranded Turtles 

 emit a deep roaring sound. In the Green, Leathery and 

 Loggerhead Turtles the shell is of little value. 



As with most aquatic reptiles, their intelligence is 

 not great, though in aquaria at least they have proved 

 capable of associating cause with effect to a limited degree. 

 In the Amsterdam Zoo it once chanced that shortage of 

 tank room necessitated associating a shoal of mullet with a 

 number of Green Turtles. As a preliminary to the fish's 

 introduction, the water was beaten and much disturbed, 



