Journal of Heredity: 5 (1914)
An Explanation of Graft-Hybrids
"M. Lucien Daniel has made a communication to the "Acadamie
des Sciences" from which it appears that the anatomical examination of
grafts of Helianthus on Helianthus and Opuntia on various cacti has
revealed to him the existence of internal adventitious roots formed in the
stock and penetrating to various depths in its tissues. Occasionally these
roots even reach the soil and bestow complete independence on the graft.
M. Daniel considers this to be the probable explanation of certain cases
of hybridization through graftingJourn. Soc. Nat. Hort. Fr., June,
1912, quoted in Journ., R. H. S., Aug., 1913."
[Editor's note: I don't know how this explains graft hybrids, but it is
interesting just the same. I have also read of a stock breaking through a
grafted bud. Daniel also grafted flower stalks of kohlrabi onto hardy cabbages.]