184 THE BOTTOM OF THE SEA. 



The pennatulse rank with animals which are gene- 

 rally phosphorescent — that is to say, which emit liglit 

 in the night. They abound most near the shores 

 of European seas. Cuvier gave them the name of 

 " swimming polypi " {Polyjoes nageurs). 



8. ActinisB— Sea-Anemones— Sea-Nettles. 



The adinse, or sea-anemones, though independent 

 (•reatures, attach themselves firmly (and for a con- 

 siderable length of time without changing their 

 locality) to the rocks. Adhesion is effected by 

 means of a large and fleshy base, which secretes a 

 glutinous matter, and it depends entirely on the 

 will of the animal. It moves from one situation to 

 another when it pleases, using its tentaculae as feet, 

 or gliding along at the bottom of the sea by a move- 

 ment which can scarcely be perceived. 



The actiniae appear imder the most varied aspects, 

 owing to the innumerable modifications of which the 

 tentaculse are susceptible, and to the diversfied cha- 

 racters of the loot itself. We may compare one of 

 these creatures to a flower plunged in water, with 

 petals so soft and flexible that they yield to its 

 slightest movements. At one moment they may be 

 seen gathered together to agitate the water, as a 

 joeans of renewing its freshness before the mouth 



