EARLY LIFE-HISTORY OF CORALS 61 



followed before we can form any conception of the real signi- 

 ficance of tlieir structure. 



The corals, like many other animals that live sedentary 

 lives as adults, are actively moving creatures Avhen young. 



Fig. 5. 



Uontlpora Colony, Dead and Dried. 



Beyond the meagre chances of distribution of living fragments 

 by the waves, and the rare transport of colonies on floating logs, 

 the adult life of a coral growth is of necessity absolutely fixed 

 in the place where it is settled down. For when a coral larva 

 becomes attached to a suitable base and lays the foundation 

 of a colony it has no further hope of translation other than by 

 chance accidents as the sport of the waves. The power of 

 active movement is lost for ever with the settling down of 

 the larva. For this adult inactivity the motile larval coral 

 compensates : the younger stages are free-swimming creatures 



