ORGANICDEVELOPEMENT. 95 



It is a just conclusion, therefore, that while the polyp, by its form, 

 and its mode and direction of growth, and mode of budding, determines 

 the general form of the zoophyte ; or, the bud, tliat of the plant, — the 

 cellule, by its form, mode, and direction of growth and mode of repro- 

 duction, determines the general form of both fiower-bud and polyp, 

 plant and zoophyte. 



93. The analogy between plants and zoophytes is, therefore, not 

 one calculated to embarass us by suggesting false affinities. On the 

 contrary, the two orders afford interesting and important illustrations 

 of the organic processes in each. We may say farther, that the 

 modes of developement throughout the animal kingdom are here 

 elucidated, and, also, with no less truth, that the principles which 

 flow from these facts, bear upon all the elaborations in organic beings. 



The tentacles of an Actinia, as also the lamellfe, which correspond, 

 are often but eight or ten in number in the young when first deve- 

 loped; but afterwards, as the Actinia grows, and the interval between 

 two lamellfe increases beyond the normal breadth (for the species), a 

 new lamella begins to form ; and so other lamellse, in succession, 

 appear. Here the same law depending on breadth of interval holds, 

 as in the developement of branches on a tree or a zoophyte. As these 

 intervals widen by growth, there is unappropriated nutriment and 

 vital force, and these acting upon the cellules intermediate commence 

 the formation of a lamella. So, also, this principle, which deter- 

 mines the scattered character of the leaves on a tree, or of processes 

 or branchlets over a coral branch, determines the closer or more 

 scattered distribution of the hairs on a leaf or an animal. A cer- 

 tain space around the reproductive point, is tributary to each hair, 

 and the size of this space is determined by the distance to which 

 the reproductive centre can exert an influence. This space is 

 measured by the intervals between adjacent hairs. But let this 

 interval enlarge, by the growth of the part, beyond this amount, and 

 immediately there is an excess of force and nutriment, which com- 

 mences the formation of a new hair. We might add illustrations, 

 but this will suffice. Reproduction proceeds on the same principles, 

 whether a hair or an animal is the result. The same is admitted 

 with respect to the developement of germinating functions in ani- 

 mals ; for it is a recognised fact, that while the growth of the body is 

 in progress, the vital forces and nutrition are dispersed in every 

 direction; but, on reaching the limits of growth, — that is, the limit 

 in radiate extent, to which the peculiar structure of the animal is 



