152 STATE HORTICULTURAL SOCIETY. 



These were grafts made upon nursery stock, and it would appear that if 

 the union were good at the expiration of the first year, it would remain 

 good throughout the life of the plant. In order to test this point I pro- 

 cured two apple trees fifteen years old and over six inches in diameter 

 which had been grafted at the surface of the ground in the nursery. In 

 the presence of two critical observers, I split the trunks into many pieces, 

 but no mark whatever could be found of the old union. The grain was 

 perfectly straight and bright through the crown. I am the more willing 

 to cite this case because I had fully expected to find a decayed or dead 

 portion or a contorted grain at the point of union; but every internal 

 evidence of a graft had disappeared. 



So far as the strength of a good union is concerned, all fruitgrowers 

 know that trees rarely break where they are grafted. There is an old 

 seedling orchard upon my father's farm into which many grafts have been 

 set. I have myself set many hundreds of these grafts in the tops of the 

 trees, often far out on large limbs; and in the immediate neighborhood I 

 have set many thousands under similar conditions; and yet with all the 

 breaking of the trees by ice, storms, and loads of fruit. I have never 

 known a well-established union to ftreak away. And I have had the same 

 experience with cherries and pears. I have lately tested the strength of 

 the union in a different way. A few days ago I cut two "stubs" from an 

 old and rather weak apple tree which had been cleft-grafted in the spring 

 of 1889. These stubs were sawed up into cross-sections less than an inch 

 thick, and each section, therefore, had a portion of foreign wood grown 

 into either side of it. These sections were now placed on a furnace and 

 kept very hot for two days in order to determine how they would check in 

 seasoning, for it is evident that the checks occur in the weakest points. 

 But in no case was there a check in the amalgamated tissue, showing that 

 it was really an element of physical strength to the plant. A similar test 

 was made with yearling mulberry grafts and with similar results; and this 

 case is particularly interesting because there were three species ungrafted, 

 — the common Russian mulberry, Morns rubra, and M. Japonica. 



From all these considerations it is evident that, admitting that hundreds 

 of poor unions occur, there is no necessary reason why a graft should be 

 a point of physical weakness, and that the statement that "grafted plants 

 of all kinds are open to all sorts of accidents and disaster," is not true. 



6. Are grafted plants less virile, — that is, less strong, vigorous, hardy, 

 shorter lived than others? It is evident that a poor union or an uncon- 

 genial stock will make the resulting plant weak, and this is a further 

 proof that indiscriminate graftage is to be discouraged. But these facts 

 do not affirm my question. There are two ways of approaching the general 

 question, — by philosophical consideration and by direct evidence. 



It is held by many persons than any asexual propagation is in the end 

 devitalizing, since the legitimate method of propagation is by means of 

 seeds. And this notion appears to have found confirmation in the con- 

 clusions of Darwin and his followers, that the ultimate function of sex is 

 to revitalize and strengthen the offspring of the union of the characters 

 or powers of two parents; for if the expensive sexual propagation invigor- 

 ates the type, asexual propagation would seem to weaken it. It does not 

 follow, however, that because sexual reproduction is good, asexual increase 

 is bad, but rather that the one is, as a rule, better than the other, with- 

 out saying that the other is injurious. We are not surprised to find, 

 therefore, that some plants have been asexually propagated for centuries 

 with apparently no decrease of vitality, although this fact does not prove 



