VI CORALS 



corals which have been brought to hght render the task 

 of compiling a complete systematic treatise on them a work 

 of such gigantic proportions that it is beyond the powers 

 of a single naturalist to complete it. All that has been 

 attempted, therefore, in this book is to place before the 

 reader a short description of a few illustrative genera of 

 each of the groups of animals and plants which form coralline 

 structures, to be a handy introduction to his studies and to 

 help him to distinguish the corals belonging to the different 

 groups. 



It is dilhcult for students at home, who have only the 

 hard skeletal parts to handle, to realise that in their natural 

 haunts the corals are living, breathing, and feeding animals 

 or plants, and no study can be complete or satisfactory unless 

 some knowledge can be gained of the structures by which 

 they capture and digest their food, the colours thev displav 

 in life, and the means by which they propagate their kind. 

 A short account of the soft parts of the coral and of their 

 appearance when alive are therefore included, wherever 

 possible, in the description of the genera. 



The accurate determination of corals is not only of 

 importance for the student of pure science, but it has its 

 economic value in the study of the problems of distribution 

 and variation of the coral reefs of the world. It may be 

 suggested that the sea-charts and marine surveys would be 

 more valuable than they are if some description were given 

 of the kind of coral of which dangerous reefs or shoals are 

 composed. If this little book will help mariners to identify 

 such corals it may serve a useful purpose. 



I regret very much that I have not been able to include 

 in the text any reference to fossil corals. The story of the 

 evolution of corals is of extraordinary interest, and the part 

 played by them in building up many of the geological strata 

 is of the greatest importance. A book deahng with this 

 subject is greatly needed, but it should be a sequel to rather 

 than a part of such a book as is now presented to the public. 



In compiHng the text I have had to consult many of 

 my colleagues in the different Faculties of the University. I 

 wish to acknowledge with gratitude their willing and valuable 



