186 THE BOTTOM OF THE SEA. 



are generally found attached to rocks in the neigh- 

 bourhood of coasts. They are almost all useless, but 

 one species is eaten in Provence and at Nice. It is 

 very soft and of a greenish colour, with brown stains 

 on the body. The extremities of its tentaculsB, often 

 very long, are frequently of a pinkish hue. 



These animals, unlike coralline polyps, are nearly 

 always found separate from other individuals of their 

 species. While other polypi are for the most part 

 bound to their native place, the actinaria are free to 

 choose their abode, and change it at pleasure. 



9. Coral — Miraculous virtue attributed to Coral by ancient tradi- 

 tion — Coral Stone— Coral Plant — Marsigli discovers the Flowers 

 of the Coral — Observations of M. Lacaze-Duthiers. 



One of the most interesting of the fixed polypi is, 

 without doubt, the coral. Naturalists of ancient 

 times regarded it as a stone, or as the solid axis of a 

 marine plant. Dioscorides thought it to be a marine 

 shrub which hardened on being taken out of the sea 

 and exposed to the air. He even thought it petrified 

 if touched while it was alive in the water. In 1585, 

 the Chevalier J. B. de Nicolai, previous to fishing 

 coral on the coasts of Tunis, persuaded a fisherman 

 to dive for the purpose of ascertaining whether the 

 coral, in situ, was hard or soft. Contrary to the 



