72 ZOOPHYTES. 
functions. This actually takes place. A polyp from those of the 
lateral surface commences to enlarge, and then to bud and lengthen, 
till finally a branch is formed, the new budding polyp being the 
parent-polyp of the branch. 
c. This change occurs at certain intervals upon the branch, though 
with considerable irregu- 
larity, depending on expo- 
sure, position, food, and 
other circumstances. The 
uniformity is, however, so 
general that a particular 
mode of branching is cha- 
racteristic of each species, 
and is readily distinguished. 
In some Madrepores, the 
branches are distant and 
long, and often between the 
|large branches, are others, 
short and rudimentary, at 
‘nearly regular intervals. 
The gemmating powers of 
the apical polyp in these 
smaller branchlets are soon 
exhausted, and only at con- 
siderable distances can one 
of them continue to bud 
and become one of the 
larger branches. ‘The late- 
ral polyps sometimes as- 
sume budding functions 
very early, and then the 
branchlets are numerous, 
and crowded. 
d. In certain species, the 
gemmating polyps are de- 
veloped only on a particu- 
lar side of a branch. In 
the horizontally growing 
Madrepores,* the new budding polyps on the main branches are con- 
* See plates 32, 33, and 34. 
