XIV 



PREFACE. 



ous parts. This cohesion will be always found to take place in the cellular 

 tissue only, and never in the vascular tissue. In the stems of all such trees as 

 are grafted by orchardists, the cellular tissue is found alive only in the medullary 

 rays and the liber; it is therefore essential, in the tirst place, that those parts, 

 both in the stock and the scion, should be placed in contact. In regard to the 

 medullary rays, these are so numerous and so closely placed, that it is scarcely 

 possible that a portion of one stem should be applied to another without the 

 medullary rays of both touching each other at many points. JNo care, therefore, 

 is required to ensure this, which may be safely left to chance. But in regard to 

 the liber, as this is confined to a narrow strip in both stock and scion, great care 

 must be taken that they are both placed as exactly in contact with each other 

 as possible, so that the line of separation of the wood and bark should, in both 

 stock and scion, be accurately adjusted. The success of grafting depends very 

 much upon attention to this. But there are other reasons why this accuracy 

 in adjusting the line between the bark and wood of the stock and scion is so 

 important. It is at that part that the roots of the latter pass downwards over the 

 former; and it is also there that the substance called cambium, which serves as 

 food for the young descending fibres, is secreted. It is obvious, that the more 

 accurate the adjustment of the line separating the wood from the bark, the more 

 ready will be the transmission of young fibres from the one to the other; and 

 that the less the accuracy that may be observed in this respect, the greater the 

 difficulty of such transmission will be. Provided the stock and scion be of 

 exactly the same size, the adjustment can scarcely fail to be accurate in the most 

 unskilful hands; it is in the more common case of the scion being much smaller 

 than the stock, that this is to be most particularly attended to. 



" Budding differs from grafting in this, that a portion of a stem is not made 

 to strike root on another stem, but that, on the contrary, a bud deprived of all 

 trace of the woody part of a stem is introduced beneath the bark of the stock, 

 and there induced to strike root. In this operation no care is requisite in secur- 

 ing the exact contact of similar parts, and a free channel for the transmission of 

 the roots of the bud between the bark and wood of the stock; for, from the very 

 nature of the operation of budding, this must of necessity be ensured. The bark 

 of the bud readily coheres with the wood of the stock, and secures the bud itself 

 against all accident or injury. But if precautions of the same nature as in graft- 

 incr are not requisite in budding, others are of no less moment. It is indis- 

 pensable that the bud which is employed should be fully formed, or what gar- 

 deners call ripe ; if it is imperfectly formed, or unripe, it ma}^ not be capable of 

 that subsequent elongation upwards and downwards upon which the whole 

 success of the practice depends. Secondly, great care should be taken, in raising 

 the bark of the stock for the insertion of the bud, that the cambium be not dis- 

 turbed or injured. The cambium is a secretion between the wood and bark, not 

 only destined to support the descending fibres of the buds, but also to generate 

 the new cellular substance within which the descending fibres are finally found 

 imbedded. If, in the preparation of the bark for receiving the bud, this cambium 

 be injured or disturbed, it becomes much less capable of effecting the cohesion 

 that is necessary, than if uninjured. In budding, therefore, the bark should be 

 carefullv lifted up, and not forced from the wood with a bone or metal blade, as 

 is usually the case; for although it is no doubt true, that an operation clumsily 

 performed will often succeed, yet it should be remembered, that if skilfully man- 

 ao-ed, it would be attended with much more perfect success; and that a habit of 

 constantly operating with delicacy will enable a gardener to succeed with cer- 

 tainty in cases in which a bungling practitioner would be sure to fiil. Little do 

 those who crush with rude hands the tender limbs of plants, reflect how delicate 

 is that organization upon which the life of their victim is dependent. 



" Transplanting is, perhaps, that operation in which the greatest difficulty is 

 generally found to exist, and in which the causes of success or failure are often 

 the least understood. Volumes have been written upon the subject, and the 

 whole range of vegetable physiology has been called in aid of the explanation of 

 the theory ; yet I am much mistaken if it cannot be proved to depend exclusively 

 upon the two following circumstances : 1. The preservation of the spongioles of 

 the roots ; and, 2. The prevention of excessive evaporation. 



" It is well known that plants feed upon fluid contained in the soil, and that 

 their roots are the mouths through which the food is conveyed into their body. 



