CHAPTER X 



CORAL ALGAE 



" Coralline is in a manner wholly spent among us to kill worms 

 in children and in elder persons, and as the matter so the manner, 

 but by what quality it worketh this effect is not declared by any, 

 for it is altogether insipide and without taste of heate or cold as 

 Corall itselfe is and if Corall be so much commended against the 

 stone and fluxes, crampes, the falling sicknesse and melancholly 

 etc. as you shall heare in its proper chapter doe not thinke but 

 these may conduce somewhat thereunto also." — John Parkinson, 

 Theatre of the Plants, 1640, p. 1296. 



A GREAT many kinds of marine Algae have their cell walls 

 strengthened by deposits of calcium carbonate. Some of 

 these retain the softness of texture and the flexibility of the 

 non-calcareous Algae and could not possibly be mistaken 

 for anything else than seaweeds ; but a considerable number 

 assume such a hard texture and calcareous aspect that they 

 are called corals not only by fishermen and sailors, but even, 

 in familiar speech, by some men of science. 



To separate these two groups of Algae is, of course, a 

 thoroughly artificial proceeding and cannot be justified on 

 any ground of vegetable morphology, but as the object of 

 this chapter is only to provide such information as will 

 enable the student to distinguish the vegetable from the 

 animal corals and to recognise some of the most important 

 forms, an artificial classification of this kind must be 

 employed. 



The discovery, by Peyssonnel and Ellis in the eighteenth 

 century, that many of the corals are animals led un- 

 fortunately to a wider and erroneous generalisation that all 

 corals are animals. 



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