CHAPTER V. 



THEORY OF ZOOPHYTIC GROWTH AND REPRODUCTION, 

 AND OF ORGANIC DEVELOPEMENT IN GENERAL. 



In the preceding pages, we have dwelt upon the structure of the 

 simple polyp, and traced out the principal steps in its germinating 

 and gemmating processes, to the production of the various compound 

 forms of life, which this class of animals presents. We propose to 

 inquire into some of the relations which the several individuals in a 

 compound mass, sustain to one another, and to illustrate the structure 

 of these animals, and the nature of the organic forces within them. 



The process of budding opens to us an illustration of the laws or 

 principles of growth and reproduction, in actual and visible progress, 

 and requires, therefore, our first consideration in these investigations ; 

 and since vegetation affords us parallel facts, there will be occasion 

 in these discussions, to recur often, and at length, to the vegetable 

 kingdom, and not so much to exhibit merely the relations of plants 

 to zoophytes, as to elucidate, by means of the facts which both pre- 

 sent, the general laws of organic developement. 



84. The reader has already perceived the relation between the posi- 

 tion of buds and the form of the zoophyte, and that in connexion with 

 the mode of growth, they determine its character even to the size and 

 direction of each branch, and the number and length of the branch- 

 ings. The facts have shown, moreover, that there is a simple law 

 governing the formation of buds, and a system in their developement. 

 In the Madrepores, which bud from a parent-polyp, — the apical one 

 of each branch, — new branchlets form at certain intervals ; of the 

 hundreds of polyps, on the lateral surface of the branches, only here 

 and there one at nearly regular intervals, becomes capable of budding, 

 and so gives origin to a branchlet : and of the budding-polyps, which 

 are thus developed, the most of their branchlets are often short; 



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