THE ATLANTIC OCEAN. 205 



the sea-plants (Zostera, &c.) on which they feed. 

 At night, the females land on the low sandy beaches, 

 and after examining the place with great caution 

 and circumspection, lay their eggs in holes, which 

 they scoop out with their fin-like feet. The work 

 being accomplished, the sand is again scraped back 

 over the eggs, and the surface made smooth as before. 

 The sun soon hatches the eggs, and the little Turtles 

 crawling forth from the sand betake themselves to 

 the sea. The usefulness of this animal as an article 

 of luxurious food is well known ; but its real value 

 can only be appreciated, when we view it as afford- 

 ing an immediate relief from the horrors of scurvy, 

 which, arising from the constant use of salted pro- 

 visions, has often proved so terrible a scourge in 

 long voyages. There is a peculiarity in the structure 

 of the heart of tliis and kindred animals, which is 

 worthy of notice. In man and other warm-blooded 

 animals, the blood is brouglit by the veins to tlie 

 heart, and poured into a chamber called the rt'fjht 

 auricle ; a communication exists between this and 

 a second chamber, called the rigJit ventricle ; from 

 tlie latter the blood is forced through a large artery 

 to the lungs, to be renewed by exposure to the air ; 

 from the lungs it is sent through veins to a third 

 chamber of the heart called tlie left auricle, and 

 thence into a fourth, called the left ventricle, from 

 which the great arteiy, called the aorta, carries it 

 again into the whole body. Thus, no particle of 

 the blood can be conveyed again into the system 

 without having passed through the lungs ; but in the 

 Turtle the case is different. All the four cham- 



