188 VEBTEBRATA 



the moment it is thrown into the water. In 1883 their 

 vast numbers completely destroyed the fishing. They bit 

 the sails or oars hanging over, and even attacked persons 

 falling overboard. They were caught by the thousands, 

 their livers being used for oil and their bodies carted to 



FlG. 218. The young of the dogfish removed from the body of its parent. Ventral 

 aspect showing the attachment of the large yolk sac to the body, and also the 

 crescentic mouth. Five gill slits are seen on one side. Photograph half natural 

 size. 



the farms for fertilizer. They feed upon refuse and smaller 

 fish. 



The blue sharks and basking sharks of the northern Atlan- 

 tic reach a length of over thirty feet, while the Indo- Pacific 

 basking shark is known to exceed forty feet in length. The 

 man-eater or white shark, ranging from the Atlantic coast 

 to Australia, seldom attains a size of more than thirty feet. 



