io8 



CORALS 



as the petals of the flower, and through the transparent 

 cyhndrical body wall may be seen thread-like structures, 

 which on further microscopical examination prove to be the 

 throat (stomodaeum), the eight mesenteries, and the eight 

 mesenteric filaments of a typical Alcyonarian polvp. 



In the months of May and June the autozooids contain a 

 number of spherical or oval bodies, and occasionally one of 

 them will squeeze through the mouth and swim away. 



Fig. 46. — A diagram to show the 

 structure of a branch of Corallium as seen 

 in transverse section. In the centre is the 

 axis (Ax.) and covering this is the coenen- 

 chym, a soft fleshy substance containing 

 the endoderm canals and spicules and bear- 

 ing the autozooids (A.) and the siphono- 

 zooids (S.). :■. 4 diains. 



Fig. 47. — Corallium nobilc. Medi- 

 terranean Sea. A., an expanded 

 autozooid. S., a siphonozooid. From 

 a drawing by H. de Lacaze-Duthiers. 

 .■ about 8 diams. 



These are the larvae, for CoralHum presents us with one of 

 the rare examples of the occurrence of viviparity in the 

 group of the Alcyonaria. Corallium nolile of the Mediter- 

 ranean is also rather exceptional among corals in being 

 hermaphrodite. Some branches of a single specimen may 

 be male and others female, or a single branch may support 

 both male and female polyps. 



When all the autozooids are fully expanded, the out- 

 stretched tentacles form an almost complete gauzy veil over 

 the surface of the branch, so that no minute organism that 



