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, 

 o'^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 always appear, 

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

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

 j)olypus, furnished with a mouth, intestines, and other organs, 

 a^ 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 tiian 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- 

 blished 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 certaintj'^, by 

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

 only casually reappear. 



