METHODS OF GRAFTING. 535 



Propagation through the agency of buds is termed gemmation. It 

 may be accomplished either by the natural or artificial separation of the 

 buds from the parent stock. Thus, in the hydra, the buds may spon- 

 taneously be separated from the parent, and thereby give rise to free in- 

 dividuals, or they may be purposely cut off with the same result. In 

 the case of plants, artificial separation is constantly resorted to, as in the 

 various methods of budding and grafting employed by horticulturists for 

 obtaining the finer varieties of flowers or fruits. It consists Methods of 

 essentially in placing a bud of the plant which it is desired to g raftin g- 

 propagate upon a stock of a different kind, in such a way that, as devel- 

 opment of the bud or scion takes place, union or incorporation with the 

 stock shall occur. There are many different ways in which grafting may 

 be performed ; they all depend for their success, however, upon causing 

 the alburnum of the scion to coincide with that of the stock, so that the 

 vessels of the former may receive the sap arising from those of the latter. 

 When the parts are thus adjusted, they are to be retained in their posi- 

 tion by bandages or other suitable means, and protected from the air and 

 rain by means of clay or wax. The most suitable time for this opera- 

 tion is in the spring, just previous to the rising of the sap. 



There are certain limits within which the operation of grafting must 

 be performed. The stock and the scion must be nearly re- Limits of gem- 

 lated to each other. If species of different natural orders be mation ' 

 grafted they will not take, but the species of the same genus may. 



If in this manner we take a bud, and graft it on a stock of an allied 

 kind, it will continue to grow and develop in the same man- Nature of 

 ner that it might have done without detachment from the propagation 

 parent plant, and in the same manner from the new plant that. bygem 

 has thus arisen, by a repetition of the process, plant after plant, for many 

 generations, can be secured. Experience has taught us that, whatever 

 might have been the peculiarities of the original from which the first bud 

 was taken, those peculiarities, whether of odor, taste, color, or shape, will 

 reappear in the product ; but experience has also taught us that thereds 

 a limit beyond which these repetitions can not be conducted. The val- 

 ued fruits and flowers of the old times have thus disappeared. Propaga- 

 tion by gemmation is therefore considered as tending to exhaust the orig- 

 inal plastic power. But it is to be remarked that, if from these artificial 

 growths seeds be taken and caused to germinate, the plants so arising no 

 longer present the special, and, perhaps, valued peculiarity, but in many 

 instances run back at once to the original and wild stock. 



We are apt to attach to propagation by gemmation more importance 

 than it really deserves in a philosophical point of view when it thus ap- 

 pears to have given rise to new and successive generations of individuals. 

 But, after all, wherein does it differ essentially from what goes on natur- 



