THE TEEMING LIFE OF THE WATERS 



water and often form extensive shoals covering great 

 distances. Sometimes, ships that happen to come upon 

 such shoals have to steer their course through them 

 for hours on end. 



Some of them are phosphorescent. I remember, 

 one night when the weather was bad, sailing across 

 the channel between the island of Aurigny and Cotentin 

 Head. This particular voyage is sometimes especi- 

 ally difficult because of the 

 strength of the tidal currents. 

 On this occasion, my boat 

 passed through a shoal of 

 large jelly-fish. Their lu- 

 minous splendour was 

 enhanced by the swiftness 

 of the current which carried 

 them along. Piled one above 

 another, they looked like 

 huge glistening spheres ris- 

 ing from the sea like set 

 pieces in a firework display 

 provided by the genii of the 

 waves, an astounding illu- 

 mination coming from the 

 very depths of the waters. 



Other floating animals 

 have translucent flesh, the 

 Siphonophores, or composite jelly-fish, the Ctenophores, 

 or comb jelly-fish, with their long tentacles, the phos- 

 phorescent sea-squirts or Pyrosomes, like knob-covered 

 little sacs made of a material as clear as crystal but very 

 strong, the barrel-like sea-squirts or Salpas, attached 

 one to another like the links of a chain stretching out 

 into the sea, the wing-footed Molluscs, or Pteropods 

 and Heteropods, several of which are covered by a 

 translucent shell. Big enough to be seen in the water; 

 so numerous, sometimes, as to cover mile after mile; 

 sometimes crowded upon one another, so that they 

 10 



Fig. 4. — Floating larva, called 

 Pluteus, of the common edible 

 sea-urchin. The adult, globu- 

 lar and spiny, about 2 inches 

 wide, lives, almost motionless, 

 on the bottom. In the larval 

 state, when it is very small, it 

 forms part of the plankton. 



