CHAP. IX.] COMPOUND ANIMALS. 203 



plant-like body producing an egg, capable of swimming about 

 and of choosing a proper place to adhere to, which then sprouts 

 into branches, each crowded with innumerable distinct animals, 

 off en of complicated organizations? The branches, moreover, 

 as we have just seen, sometimes possess organs capable of move- 

 ment and independent of the polypi. Surprising as this union 

 of separate individuals in a common stock must ahvays appear, 

 every tree displays the same fact, for buds must be considered 

 as individual plants. It is, however, natural to consider a 

 polypus, furnished with a mouth, intestines, and other organs, 

 as a distinct individual, whereas the individuality of a leaf-bud is 

 not easily realised ; so that the union of separate individuals in 

 a common body is more striking in a coralline than in a tree. 

 Our conception of a compound animal, where in some respects 

 the individuality of each is not completed, may be aided, by re- 

 flecting on the production of two distinct creatures by bisecting 

 a single one with a knife, or where Nature herself performs the 

 task of bisection. We may consider the polypi in a zoophyte, or 

 the buds in a tree, as cases where the division of the individual has 

 not been completely effected. Certainly in the case of trees, and 

 judging from analogy in that of corallines, the individuals pro- 

 pagated by buds seem more intimately related to each other, than 

 eggs or seeds are to their parents. It seems now pretty well esta- 

 blisiied that plants propagated by buds all partake of a common 

 duration of life ; and it is familiar to every one, what singular 

 and numerous peculiarities are transmitted with certainty, by 

 buds, layers, and grafts, which by seminal propagation never or 

 only casually reappear. 



