1 82 TOILERS IN THE SEA. 



haps muscular, coats, and are filled with a much less 

 consistent matter than that of the body of the polyp 

 itself. Hence it appears that many polypes commu- 

 nicate together, and form a compound animal. The 

 space between the tubes is occupied by a loose 

 fibrous tissue, with the interstices filled with a trans- 

 parent gelatine, in which lie numerous irregular 



FIG. 34. 



spicules. These spicules are mostly of the form of a 

 cross, and toothed on the sides, formed of carbonate 

 of lime (fig. 34), and have no organic connexion 

 either with the tissue or the tubes. The ova are 

 contained in the polyp tubes; they are white at 

 first, but at length become of a scarlet colour, 

 opaque, globose, and about the size of a grains 

 of sand ; ultimately they are expelled from the 

 mouth. 1 The polyp-masses are of a greyish white 



1 " History of British Zoophytes." By George Johnston, M.D. 

 (London, 1847.) Vol. i. p. 175. 



