140 TRANSPLANTATION. 



and the scion is so much interrupted that the sap can no longer ascend 

 with sufficient rapidity into the branches, the latter die ; as in many Peaches, 



348. This incomplete union between the scion and its stock is owing to 

 some constitutional or organic difference in the two. 



349. Therefore, care should be taken that when plants are grafted on one 

 another, their coustilution should be as nearly as possible identical. 



350. As adhesion of only an imperfect nature takes place when the scion 

 and stock are, to a certain degree, dissimilar in constitution, so will no ad- 

 hesion whatever occur when their constitutional dirfierence is very decided. 



351. Hence it is only species very nearly aUied in nature that can be 

 grafted on each other. 



352. As only similar tissues will unite (19), it is necessary, in applying 

 a scion to the stock, that similar parts should be carefully adapted to eacb 

 other ; as bark to bark, cambium to cambium, alburnum to alburnum. 



353. The second is more especially requisite, because it is through the 

 cambium that the woody matter sent downward by the buds must pass; 

 and also because cambium itself, being organizing matter in an incipient 

 state, will more readily form an adhesion than any other part. 



354. The same principles apply to buds, which are to scions precisely 

 what eyes (319) are to cuttings. 



355. Inarching is the same with reference to grafting, that layering (324) 

 is with reference to striking by cuttings. 



356. It serves to maintain the vitality of a scion until it can form an 

 adhesion with its stock ; and must be considered the most certain mode 

 of grafting. 



357. It is probable that every species of flowering plant, without excep- 

 tion, may be multiplied by grafting. 



35S. Nevertheless, there are many species and even tribes that never 

 have been grafted. 



359. It has been found that in the Vine and the Walnut this difficulty 

 can be overcome by attention to their peculiar constitutions ; and it is pro- 

 bable that the same attention will remove supposed difficulties in the case 

 of other species. 



XV. Transplantation. 



360. Transplantation consists in removing a plant from the soil in which 

 it is growing to some other soil. 



361. If in the operation the plant is torpid, and its sponjrioles uninjured, 

 the removal will not be productive of any interruption to the previous 

 rate of growth. 



362. And if it is growing, or evergi-een, and the spongioles are uninjured, 

 the removal will produce no farther injury than may arise from the tem- 

 porary suspension of the action of the spongioles, and the non-cessation 

 of perspiration during the operation. 



363. So that transplantations may take place at all seasons of the year, 

 and under all circumstances, provided the spongioles are uninjured. 



364. This applies to the largest trees as well as to the smallest herbs. 



365. But as it is impossible to take plants out of ttie eartli withoiit 

 destroying or injuring the spongioles, the evil consequence of such acci- 

 dents must be remedied by the hindcrance of evaporation. 



