BOTANICAL GAZETTE. 



Vol. IV. 



JUNE, 1879. 



No. 6. 



Influence of the Scion on the Stock. — It is now very well known 

 that many of onr variegated varieties of green house AhutiJoiis are 

 produced by budding. A species witli a variegated leaved form is 

 grafted on another species, and from the branches which spring from 

 the stock beneath the bud or graft, come out in some cases variega- 

 ted ones — the same as the stock in all cases. There is no hybridity, 

 only the variegation is communicated to the sprout from the stock. 



Three years ago a bud of the blood-leaved variety of Betuln alba 

 was put into a strong stock of B. alba, var. popuJifoJIa, our American 

 form. The following spring the bud made a growth of nearly a foot 

 in length, when a careless laborer pushing against it. knocked the 

 growing shoot completely out. Over the place where it grew a bud 

 of the cut-leaved Birch was inserted, which, growing, caused the 

 stock to be preserved. Last spring, several inches below the place 

 where the original bud of the blood-leaved variety had been torn out, 

 a branch of a l)lood-leaved color pushed forth. It attained a height 

 of nearly two feet the past summer, and the stock still shows the scar 

 of the original bud. That such transfusion of cluiracter can be carried 

 downward in tlie stock is not new, as already noted in Abiitikjn, but I 

 think it is new that this coloring principle can exist in the stock for 

 ten months after all the foliage has been destroyed, and nothing but 

 a portion of the original bark of the bud remained. 



Another novel point is that whereas in other cases only the ''varie- 

 gating materiar' has been transfused downwards, the sj)ecific, or it 

 may be varietal, character remaining intact; in tliis case the new bud 

 from the populifolia stock is the true European iill)a, showing that in 

 this case more character than tiiat of mere coloring has been trans- 

 mitted through the structure of llie stock. I may remark that many 

 botanists receive B. populifolia as l)ut a variety of I>. alba. As long- 

 as it is not possible to define what is a species, there may be an al- 

 lowable difference of opinion, but it seems to me there are as many 

 permanent distinctions as in many other universally acknowledged 

 species of plants. There is one distinction which I have never seen 

 noted. In B. popidi folia the leaves spread Hat at once in expanding, 



