CORALLINES. 



235 



The simple isolated state of the animal, whose phases of develop- 

 ment we have indicated, does not last long. It possesses the property 

 of producing new beings, as we have already said, by budding. But 



Fig- 93- Young Coral Polyp attached to a Rock, Fig. 94. A Rock covered with young Polyp 

 and expanded. (Lacaze-Duthiers.) and Polypidom. (Lacaze-Duthiers.) 



Fig. 95. Corpuscles from which originate 

 the Polypidom. 



Fig. 96. First form of the Polypidom. 

 (Lacaze-Duthiers.) 



how is the polypidom formed ? If we take a very young branch, we 

 find in the centre of the thickness of the crust a nucleus or stony 

 substance resembling an agglomeration of spicula. When they are 

 sufficient in number and size, these nuclei form a kind of stony plate, 



