THE SHARK'S TEETH 



feet in length, and are correspondingly broad; their 

 girth being sometimes more than thirteen feet. These 

 huge monsters, which are almost as strong as the 

 strongest whales, have a mouth whose size is in 

 keeping with their proportions. This, like that of 

 other sharks, is placed underneath the head, which 

 ends in a great snout. But in size they are equalled 

 and even surpassed by the whale sharks, which, con- 

 trary to the usual rule, have mouth and nostrils in the 

 front, though they are as large as usual. These 

 massive giants are fearful to look at, but they are 

 practically harmless. They have size, weight, muscular 

 vigour, and a mouth of large size but almost devoid 

 of teeth. The jaws of the basking shark, in proportion 

 to the size of the creature, are furnished with minute 

 teeth, several thousands in number, but only a few 

 millimetres in length. And when we come to the 

 whale sharks, the state of affairs is even more striking: 

 the teeth are more like the roughness of a file: to all 

 intent, indeed, these sharks are toothless. 



So these enormous sharks, whose greediness is no 

 less than that of their smaller allies, have to secure 

 their nourishment without the assistance of the more 

 complex and powerful dentition possessed by the 

 others. The capacity to snap up their prey is sufficient 

 for them. The creature's swiftness, which allows it to 

 overtake most other animals of the sea, and the breadth 

 of its large open mouth, provide it with all the necessary 

 facilities for seizing and swallowing in one gulp. 



When we consider this deficiency in the outfit of 

 teeth we might think it a case of transformation through 

 falling into disuse, that is to say, by a gradual lessening 

 or cessation of use. As the function becomes less 

 necessary, the system whose business it is to accomplish 

 that function is correspondingly reduced. If this were 

 so, there would exist a formal relation between the two, 

 not independence. But Nature herself shows the error 

 of any such presumption. We must note the restric- 



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