ON THE OUTER REEF. 57 



them. "What a time the young sharks must 

 have when cutting their teeth ! " 



" Yes," said Harry, feeling of the terrible 

 weapons, "and each one is saw-like and sharp as 

 a knife." 



" All the teeth except the front row lie flat," 

 explained the doctor, "when not in use. As 

 you see, they move up and down ; but when the 

 shark was after the ray I feel sure they were all 

 vertical and ready for action." 



For his share of the prize the boatswain took 

 the liver, intending to try out the oil. 



" Sharks are not entirely worthless animals, 

 you see, after all," said the doctor. "The teeth 

 are used by many savage islanders for weapons, 

 the liver is taken out for the oil it contains, and 

 in the East the tails and fins are valuable arti- 

 cles of commerce, while the skin, as with us, is 

 used for various purposes." 



" What do you call this shark that we have 

 caught, doctor ? " asked Harry. 



" It is a shovel-nosed shark," he replied. 

 " There are at least a hundred different species 

 of sharks now known to naturalists, and this 



