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and by grafting and was grown in the gardens of Florence for its 
decorative value. It was described by certain botanists and 
horticulturists as a sex-hybrid and by others as a graft-hybrid. 
A search in the older literature has shown that an early account 
of its origin states that the first branch came from a callus at the 
base of the dead scion of a graft between the orange and the 
citron. : 
Another so-called graft- neal originated in 1825 in the garden 
of a French gardener by the name of M. Adam. From a graft of 
Cytisus purpureus on ee vulgare a branch arose that was 
somewhat intermediate in character between these two species. 
This branch was propagated . eas The plants thus pro- 
duced gave some branches t were pure Cytisus purpureus, 
others that were partly C. oe and partly LD. vulgare and 
still others that were intermediate in character. This interest- 
g plant led to much discussion among botanists and _horti- 
altura Some claimed that it was a vegetative hybrid result- 
from the actual fusion of two different kinds of cells which 
met at the juncture of the scion and the stock, while jae 
among whom were several eminent botanists, considered that the 
branch used as a scion by M. Adam was itself taken ie a 
plant that was a sex-hybrid between the two species involved in 
the graft. 
Several types of supposed graft-hybrids between the white- 
thorn (Crataegus monogyna) and the medlar (Mespilus germanica) 
were also well known. In the growth of these there is seen the 
same sorts of development with reference to the characteristics 
of the two parents as are noted in the plants of Cyttsus Adami. 
The first step in determining the nature of such “‘ mixed plants” 
was to a produce them under observation and control. 
simple but i es ahs method of experimentation, Dr. 
a undertook to do this. He used the tomato and the 
nightshade, two distinct a well- known species with marked 
differences in leaves, flow and fruit. He made reciprocal 
grafts, using the cleft or ae. -graft. When the scion was well 
established he decapitated the branch cutting through the points 
of contact between the scion and the stock, thus exposing on the 
