FOUNDERS OF PLANT BREEDING 
297 
from other families, have never shown themselves to be different 
from those of the mother plants.” 
In the valley of the Nagold, in the Black Forest region of 
Wurttemberg, some forty miles southwest of Stuttgart, the capital, 
lies the village of Calw. Here Koelreuter, whose home was in 
Sulz, did some of his work on hybridization, in the garden of a 
local physician. By a curious coincidence, in the same village 
of Calw . lived and died Carl Friedrich von Gartner , who for 
twenty-five years conducted experimental work in hybridization. 
An idea of the amount of labor expended by Gartner during the 
twenty-five years of his hybridization experiments may be obtained 
by the statement that he carried out nearly ten thousand separate 
experiments in crossing, among about seven hundred species, be- 
longing to eighty different genera of plants, and obtained in all 
some two hundred and fifty hybrid plants as the total result. 
Gartner, recognized, as did the other hybridizers of his day, that 
there was always a difference between the first and the succeeding 
generations, the former being uniform, the later ones variously 
splitting up. Gartner did not fail to recognize the fact of un- 
usual vigor in hybrids, although he does not distinguish as to the 
generation. Gartner derived, from his long experience, a cer- 
tain philosophy concerning the nature of hybrids which is note- 
worthy. He recognized an inequality in the influence or the 
“potency” as he termed it, of one parent over another in a cross, 
which potency was maintained, whichever way the cross was 
made. Gartner, not having the knowledge which has come since 
and in consequence of Mendel’s investigations, sought a theoreti- 
cal explanation for this phenomenon of dominance and gave it 
the designation of “sexual affinity” in the crossing of species, 
the magnitude of which he considered could be measured by the 
number of viable seeds produced in the cross. Gartner did not 
realize, in spite of Sageret’s experiments, that some individual 
characters of a parent might be found to dominate in a cross and 
others not. Gartner’s work is noteworthy, not only for the re- 
markable number of species with which he experimented but for 
the scrupulous care which he exercised in his operations. 
During the time of the prosecution of the work of Knight and 
Herbert, appeared the results in hybridization obtained by 
Sageret in France. Sageret’s experiments in crossing were large- 
ly confined to the Cucurbitaceae, and his results were published 
in a memoir entitled: “Considerations sur la production des hy- 
