54 CORALS AND CORAL ISLANDS. 
4 
New branches are made in such species by a forking of an 
old one, The budding cluster enlarges as it grows, and, when 
it is just beginning to pass the regular or normal size for the 
species, a subdivision of the budding cluster commences at the 
extremity of the branch. It is a process of spontaneous fis- 
sion of a branch or stem. In this way the forking in the coral 
of the figure on page 52 was produced, and also the branching 
in that on page 53. 
Sometimes, again, the budding cluster is a linear series ; 
and then a coral with erect, flattened or lamellar branches is 
made. 
Again, sometimes each branch of the corallum is only 
the corallet of a single polyp ; and new branches are added by 
the budding of new polyps trom its sides, each to lengthen out 
into a new branchlet. In this manner the coral here figured, 

CLADOCORA ARBUSCULA, LEs. 
a common species of the West Indies, and also that of fig. 1 on 
Plate LV., a Caulastrea, from the Feejee group, were formed. 
When the budding is not confined to any particular polyp, 
or cluster of polyps, but takes place universally through the 
growing mass, the coral formed is more or less nearly hemi- 
spherical; and often the process goes on with such extreme 
