MADREPORES. 



109 



FRAGMENT OF MADREPORE. 



CELL OF THE MADREPORE. 



In the living madrepore, every part of the surface 

 of each stem is covered over with a living gelatine, 

 furnished with millions of minute polyps that issue 

 from the multitudes of cavities observable on the sur- 

 face of that substance. The following engraving illus- 



