. Coral and atolls: a history and description of the Keeling-Cocos Islands, with an account of their fauna and flora, and a discussion of the method of development and transformation of coral structures in general. Coral reefs and islands. GROWTH OF THE CORAL COLONY 83 the " dominant zooid" is marked off from its distinctive anatomical feature, for it is sym- metrical. Of tlie many thousands of daughter zooids budded off" from the " dominant zooid," all are not alike; the great bulk are asym- metrical, and are but little raised from the general surface of the coral, bu
. Coral and atolls: a history and description of the Keeling-Cocos Islands, with an account of their fauna and flora, and a discussion of the method of development and transformation of coral structures in general. Coral reefs and islands. GROWTH OF THE CORAL COLONY 83 the " dominant zooid" is marked off from its distinctive anatomical feature, for it is sym- metrical. Of tlie many thousands of daughter zooids budded off" from the " dominant zooid," all are not alike; the great bulk are asym- metrical, and are but little raised from the general surface of the coral, but here and there a prominent and symmetrical zooid is given off. Like the " dominant zooid," these lateral zooids possess the power of perpetual growth, and they are the agents in forming the lateral branches. Under certain conditions only very few of these prominent lateral zooids are produced, and then the resulting vegetative growth consists of long straight stems with but few side-branches. The typical form of vegetative growth of the Madrcpora is therefore a branching system, but many variants of this form are developed normally and abnormally. Pseudo plate-like growths are common, and they are formed by the anastomosis of numerous branches in one plane. Again, the importance of the " domi- nant apical zooid " is variable, and some types branch more after the type fashion of the Monti-pora, for a whole apical series of zooids may be symmetrical. fellows by a Fig. 21. Having now reviewed, in some measure, the various methods of the formation of the vegetative growth of colonies, it is necessary to see how far these forms of growth are to be reckoned as specific qualities. Here a great diffi- culty arises, for an enormous amount of time and careful experiment must be devoted to the proving or disproving. Vegei'aiive Eepro- DUCTiON IN Corals. Diagrammatic section to illustrate the mode of growth of Madrepora: the " dominant apical zooid" is the o
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Keywords: ., bookauthorjonesfwo, bookcentury1900, bookdecade1910, bookyear1912
