IOO 



THE SEAS 



jointed armour, and has a prehensile tail. There is a near 

 relative of this fish which lives in Australian waters 

 (Phyllopteryx eques) that is a piece of living camouflage 

 (Fig. 19). All the knobs and spines on its body are pro- 

 longed into leaf-like filaments, which give the fish exactly the 

 appearance of the brown sea weeds amongst which it lives. 

 The Torpedo, or Electric Ray, a member of the skate 

 family, is remarkable for possessing on either side of its 



head two organs capable of 

 generating quite powerful 

 electric discharges. The electric 

 organs are composed of mus- 

 cular tissue in the form of 

 innumerable small cells verti- 

 cally arranged, the top surface 

 of the organ being electro- 

 positive, and the bottom electro- 

 negative. A large fish of this 

 species can give a shock suffi- 

 cient to paralyse temporarily 

 the arms of a strong man. At 

 least one species occurs at times 

 on the British coasts, but the 

 majority live in warmer seas. 



Fig. 19. — Phyllopteryx eques, 

 a sea-horse (x £). 



Whales 



Whales are not fishes. They 

 belong to the mammals, that large group of the animal 

 kingdom the great majority of which live on dry land. 

 Whales are in fact four-footed animals that, in the 

 Jong course of evolution, have taken to the water 

 for their permanent abode. Their external structure 

 has, however, become so changed that they are almost 

 fish-like in appearance, having the typical spindle shape 



