50 CORALS AND CORAL ISLANDS. 
rising stem is formed with one parent polyp at the extremity 
of the stem, and a terminal corallet to the corallum, or to each 
branch of it. This is the case in the genus Madrepora, a 

MADREPORA ASPERA, D. 
species of which is here represented. Each branch in the 
living state had at its extremity the parent polyp of the 
branch, or that whose budding made the other polyps of the 
branch. In such species, a new lateral branch is commenced 
by one, among the many polyps over the surface of a branch, 
beginning to grow and bud. Thus branch after branch is 
added, and the little tree produced. 
Another kind of coral, growing and budding in the same 
manner, is represented on page 51. It is a species of Dendro- 
phyllia, from the Feejees—a genus often presenting tree-like 
forms, as the name implies. 
In other cases, budding goes on until a cluster of some size 
