﻿2 MADREPORAEIA. 



may show a very great development of coenenchyma ; and on the other hand, individual 

 Montiporine colonies may be so thickly beset with calicles that the ccenenchyma appears 

 comparatively scarce. These are merely individual variations within the limits of each genus, 

 variations which appear at times to carry the types concerned beyond bounds, to the dissolu- 

 tion of one's system of classification. It is, indeed, the test of a natural system that the 

 limits of the different genera can stand the strain of all the possible individual variations 

 among their respective species. 



In spite, then, of individual variations, the Montiporinse may be generally described as 

 colonies of polyps in which the porous walls have been thickened and specialised at the 

 expense of the polyp ca^'lties. The characteristic of the subfamily, therefore, is enormous 

 development of the coenenchyma with very feeble development of the calicles. Hence, of all 

 the Madreporidffi, the Montiporinaj deserve before all others the title of ccenenchymatous 

 corals. They come very fittingly at the end of the Madreporidas, for in the Madreporinae the 

 coenenchyma is a secondary and more or less subordinate tissue cementing the calicles 

 together, and thickening the basal supports of the colony as a whole, the calicles themselves 

 taking the lead in the building up of the stock ; but in the Montiporinte, this secondary tissue 

 has become to all appearance the most important factor in the colony, not only forming the 

 greater part of its mass, but developing all kinds of protective structures among which the 

 degenerate polyps can lurk. So great, indeed, is the range of variation in the plastic ccenen- 

 chyma, as the following pages will show, that Montipora will in all probability ultimately 

 prove to be richer in species than any other genus of Stony Corals. 



In the following pages, these different ccenenchymatous specialisations are systematically 

 arranged, where possible, in such a way as to show the lines along wMch they have travelled. 

 The greater part of the volume is occupied with the genus Montv^ora, within which these 

 often marvellous and beautiful variations have free play. The small concluding section deals 

 with the interesting genus Anaci'0]pora, which is, in reality, little more than a group of very 

 specialised Montipores. Its relations with the principal genus will be discussed in detail in 

 the morphological introductions. 



