GROWTH OF THE CORAL COLONY 89 



may be collected, up to the highly developed lagoon types, 

 with branches many feet in length. 



Exactly the same results are produced in the Focillo2)ora, 

 and here the rough-water type is a flattened growth, with 



Fig. 24. 



a b c 



Types of Growth of Madrepora. 

 a. In barrier pools, h. In deep water, c. In rough water. 



irregular divisions into separate lobes ; each lobe representing 

 a separate branching system. 



The Millepora also show well-marked rough-water types; 

 and that named M. verrucosa is the form which lives in the 

 crash of the surf. 



Any coral that chances to establish its colony in rough 

 water exhibits, therefore, one well-marked characteristic : it 

 always tends to form a rounded or flattened mass ; and this 

 for obvious mechanical reasons. It is a direct outcome of the 

 conditions of the environment, and any zooid must conform 



