438 The Commercial Products of the Sea. 



its development is simple, and accommodates itself to very" 

 varied circumstances ; that detached fragments from the 

 bunch or principal stem have a vitality, and will volun- 

 tarily attach themselves to certain fixed substances, for 

 continuing their development and forming new trunks ; in 

 fact, objects thrown into the sea in the vicinity of coral 

 banks will infallibly be found covered with coral in a few 

 months. But what is most valuable to be known in regu- 

 lating the search for coral, and for rendering the return 

 more productive and more certain, is to ascertain at what 

 age coral attains its largest size ; how long it takes for an 

 exhausted coral bank to again become rich and flourishing- 

 at what period the eggs are laid ; how are the products 

 disseminated ; at what period does the budding take place, 

 and how long does it last ? These are most important 

 questions, on the solving of which rests the complete 

 regeneration and progressive increase of the coral fisher)', 

 and they are questions as yet unsolved by naturalists. 



Professor Lacaze-Duthiers, who was charged with a 

 mission to the coast of Algeria to report upon this zoophyte, 

 has given us the results of- his investigation and curious 

 experience : — 



" To describe correctly," he says, " a branch of coral 

 we must bear in mind the peculiar property of germination 

 which belongs to the immense class of zoophytes, and we 

 can then consider it as a cojony of individuals derived 

 from one zoophyte, itself originating from an ovum or 



egg- 



" The stem of the coral is divisible into two constant 



and distinct parts : a central axis, hard and brittle, like 

 stone, which is the part used in commerce, and a soft cover- 

 ing or epidermis, which easily yields to the nail when it is 

 fresh, but is friable or brittle when dry. 



