116 
EOYAL HOETICXJLTUBAL SOCIETY. 
in the male differ from a variation in both but in degree ? Most 
of Mr. Wallace's instances of dimorphism are of this character — 
the male being the same in a number of islands in each of which 
the female differs. All these I regard as mere instances of 
climatal variation, in which the variation shows itself only in that 
part of the species called the female. An occasional case of vari- 
ation from some other cause, as from hybridism, may possibly 
come to complicate this phenomenon ; but it appears to me to be 
sufficiently explained by variation ; and the circumstance above 
mentioned is significant, that where mimicry occurs in species 
having dissimilar sexes, it, too, is often confined to the female. 
XIII. On Grafting and Budding. By A. Mueeay, Esq., F.L.S. 
The changes which have taken place at Chi s wick aff'orded so 
favourable an opportunity of procuring specimens and sections 
of the grafted portions of fruit-trees of diff'erent kinds, that it 
seemed to me desirable to use the opportunity to make up for 
the Horticultural Society a case of specimens illustrative of graft- 
ing which might be placed alongside of the cases of Economic 
Entomology for similar purposes of instruction. 
I have been the more induced to do so from the circumstance 
that Mr. Barron, our able superintendent, informs me that he 
finds the theory and practice of grafting to be so little under- 
stood by the young gardeners who come to complete their educa- 
tion at Chiswick, that it is rarely that any of them are able to graft 
successfully until after the erroneous notions with which they come 
impregnated are eradicated and corrected. It seems that the 
drawings and woodcuts which are given of the process of grafting, 
by the most eminent writers on the subject, almost always convey 
an erroneous impression on the very point on which success 
entirely depends. The woodcuts of the slips and grafts prepared 
for adhesion turn the attention more to an equality of dimension, 
and to a correct fitting of the outside of the bark of the one to 
the outside of the bark of the other, than to an exact apposition 
of cambium of the one to that of the other, on which, in point of 
fact, adhesion and grafting absolutely and solely depend. 
It appears to me that the exhibition of the specimens I have 
obtained for the Society's case may serve to bring before the eye 
