152 
POPULAR SCIENCE REVIEW. 
The case that has attracted most attention on the part of 
botanists and physiologists is that of the laburnum known in 
gardens as Cytisus Adcimi. This plant is stated to have origi- 
nated in a French nursery from the insertion of a bud of the 
shrubby Cytisus jpurpureus on to the common Cytisus Labur- 
num . At any rate, great astonishment is excited year after year, 
as the tree produces the long racemes of the yellow-flowered 
laburnum and the shorter tufts of the purple Cytisus , while some- 
times the colours of the flowers are mingled in the same raceme ; 
and, indeed, every intermediate form is produced between the 
two species above enumerated. Those who dispute the origin of 
this tree from grafting attribute its peculiarities to the cir- 
cumstance that it is a hybrid formed in the ordinary way by 
cross fertilisation, and that the two-faced appearance the plant 
puts on is simply the effect of the disunion of the mingled 
characteristics such as is now known to occur frequently among 
hybrid plants. But against this view there are certain circum- 
stances to be recorded. First, the history of the plant, according 
to which it decidedly originated in a graft. The nurseryman 
could hardly have been mistaken in such a case, and there is no> 
reason whatever to question his veracity. Secondly, attempts that 
have been made to produce the plant by pollen-fertilisation in 
the way suggested have not been successful. Were this a solitary 
case one might hesitate to accept it as a case of graft-hybridisa- 
tion, but it is not unsupported by evidence of a similar cha- 
racter, as we have already shown. Even in the laburnum, Mr, 
Purser has produced a precisely similar effect by grafting the 
purple Cytisus on to the yellow-flowering-species. No doubts 
have ever been raised as to the correctness of this statement. 
We may further cite the case of a Devoniensis rose budded 
on a White Banksia, and wherein from immediately above the 
graft arose a branch which was neither White Banksian nor 
Devoniensis, but partook of the characters of both. This may be 
represented diagrammically, as in the figure : — 
1 represents the stock ; 2 the graft, or bud ; & 
the mixed product. 
Other illustrations have been cited in roses,. 
________ one of which is shown in the accompanying illus- 
t ra ti 0 n(Plate LXXI.), and wherein a white moss- 
rose is shown springing from the same branch as a smooth-barked 
red Quatre-Saisons rose. The graft in this case was effected 
close to the ground while the two flowers were borne two- 
feet above it. Those who disbelieve in the possibility of graft- 
hybridisation attribute such a case as this to the separation 
between the heretofore mixed elements of an ordinary hybrid. 
Not long since a well-known French horticulturist, M. 
Carriere, put on record a case in which he grafted a scion of 
