72 



ZOOPHYTES. 



Fig. 32. 



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. 



