218 CHARLES DARWIN 



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 concep- 

 tion of a compound animal, where in some respects the indi- 

 viduality of each is not completed, may be aided, by reflecting 

 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 propagated by buds seem more 

 intimately related to each other, than eggs or seeds are to 

 their parents. It seems now pretty well established 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. 



