58 



THE STORY OF LIFE IN THE SEAS. 



the natural history of Corals a statement is made 

 to the effect, that the Polyps construct the Coral 

 in much the same way as Bees build their hive, 

 or a Bird its nest. This very erroneous view 

 coincides closely with ideas which might easily 

 be gained by a casual observation of corals in a 

 museum. The lime is not, however, collected as 

 such from the sea by the Coral-polyps and 

 plastered round their bodies to form a hous 



or shelter, but it 

 is formed as a 

 secretion by the 

 activity of certain 

 organs of the 

 animal's body, and 

 is consequently a 

 true shell or skele- 

 ton. In a Coral, 

 which is formed 

 by a colony ot" 

 numerous Polyps 

 the shell secret 

 by each individua 



FIG. 19. Polyp of a Madrepore Coral, show- fuses OU to thos 

 ing the canals by which it is connected .~J v. r 



with its feiiows. termed by 



neighbours, and 

 thus a communal shell is formed which may 

 assume a most complicated branching, bushy 

 form, according to the species of the Coral and 

 the conditions that are favourable or unfavour- 

 able to the nourishment and growth of the 

 different parts of the colony. In such a Coral 

 the Madrepore every individual Polyp is con- 

 nected with its neighbours by a system of 



