68 CORALLINES. 



to each plumose branch ; and as the whole zoo- 

 phyte, being three feet long, bears these plumes, 

 on an average, every half inch on opposite sides, 

 the whole number of polyps is not less than 

 eight hundred millions ; all the offspring of a 

 single germ, and produced by successive bud- 

 dings. 



Lister mentions a curious fact in reference to one 

 of these corallines : " After I had kept the clusters 

 in a large bowl for two days, I observed the animals 

 to droop and look unhealthy. On the third day, the 

 heads were all thrown off, and lying on the bottom 

 of the vessel, of a pink colour, and when it had stood 

 quietly for two days, it became a very fine powder. 

 Thinking that the tubes were dead, I was going to 

 throw them away, but I happened to be under the 

 necessity of quitting home for two days, and on my 

 return, I found a thin transparent film being pro- 

 truded from the top of every tube. I then changed 

 the water every day, and in three days every tube 

 had a small body reproduced upon it. The only 

 difference I could discover in the structure of the 

 young from the old heads, consists in the new ones 

 wanting the small red papilla with which the others 

 are provided, and in the absence of all colour in the 

 animal ! " 



A variation from the last-noticed form is apparent 

 in another coralline, which adheres to rocks and shells 

 near low-water mark, and is also found in deep 

 water. This elegant species, which is very common, 



