DIFFERENT WAYS OF SWIMMING 



two sea -turtles known as logger - heads, common 

 enough upon our coasts. Living well out to sea, near 

 the fish upon which they feed, they are sometimes 

 caught in the fishermen's nets. They live quite 

 comfortably in an aquarium, for they are marine 

 reptiles with lungs, and breathe air. Their general 

 shape is like that of the tortoises of our gardens, but 

 they are built on a larger scale. Their carapace is 

 thick, but not so domed; their mobile head armed 

 with a blunt beak, but stronger. But the limbs are 

 different. In place of the short, massive, column-like 

 paws to which we are accustomed, which give to the 

 land tortoise that heavy slowness which has become 

 proverbial, the marine turtles have long, firm, scaly 

 fins, which they use very effectively. Their four 

 limbs, both front and back, especially the former, are 

 powerful oars, which impel the body, in spite of its 

 massiveness, swiftly and continuously. These turtles 

 are among the finest swimmers in the sea. 



It is easy to see how they progress, and their move- 

 ments are worthy of attention. The front, or brachial, 

 limbs are larger than the hind limbs, and do the most 

 work. If, as regards situation, their nature as front 

 limbs, and function, they correspond to the pectoral 

 fins in fishes, they differ from them by a better 

 articulation with the shoulder, conferring greater 

 mobility. They can turn in every direction, on their 

 area of attachment. When the animal is swimming, 

 it begins by bringing them forward and joining them 

 in front of the head, like a swimmer preparing to dive. 

 It then sweeps them back sideways, extends them to 

 their full length, presses the water with their whole 

 surface, and prolongs their movement to its extreme 

 limit. Their tip, in a displacement of such magnitude, 

 describes almost a complete half circle. Stronger and 

 better placed than their counterpart in the fish, they do 

 their work more effectively. 



Near the turtles, in the tank and swimming not far 



5° 



