HYBRID INTERMIXTURES. 
371 
think their value will be fully ascertained from the present 
crop. 
There seems no reason to doubt that better varieties of 
wheat, oats, and barley may yet be obtained by combining 
the hardiness of one, with the productiveness of another 
sort, and the finer skin or greater weight of a third. I 
am inclined to think that I have derived advantage from 
impregnating the flower, from which I wished to obtain seed, 
with pollen from another individual of the same variety, or 
at least from another flower, rather than with its own ; and 
as races of animals are known to degenerate, if they are perpe- 
tuated by the union of near kindred, it seems not unlikely 
that vigour may be given also to any race of vegetables by 
introducing across, though of the same kind, and especially 
from an individual grown in a different soil or aspect. To 
illustrate this, I will state a circumstance which occurred 
last summer in my stove. Nine very fine crosses of Hippe- 
astrum were flowering there at the same time ; one a natural 
seedling from Johnsoni or Regio-vittatum, two Johnsoni-pul- 
verulentum, one Johnsoni-vittatum, one Psittacino-Johnsoni, 
one from Psittacino-Johnsoni crossed again by Vittato-John- 
soni, one from Johnsoni by Solandriflorum, and two from Vit- 
tato-Johnsoni by the same. Being desirous of blending again 
these plants which were all cross-bred, different flowers were 
touched with pollen from their several neighbours and tick- 
eted, and other flowers were touched with their own pollen. 
Almost every flower that was touched with pollen from ano- 
ther cross produced seed abundantly, and those which were 
touched with their own either failed entirely or formed slowly 
a pod of inferior size with fewer seeds, the cross impregna- 
tion decidedly taking the lead. It appears to me that this 
circumstance may be analogous to the introduction of a male 
from another flock or herd, which has been found advanta- 
geous to the breed of domestic animals ; and I would advise 
gardeners to try the effect of setting flowers with the dust 
from another individual in preference to their own, with a 
view to obtain an improved breed. 
It is only from the superior efficacy of the pollen of another 
plant, that we can account for the circumstance of some hy- 
brid plants, which breed freely with plants of either parental 
stock and fecundate them, not producing seed readily when 
left to themselves; for if their pollen is able to fertilize, and 
their ovary to be fertilized, there can be no positive sterility 
2 b 2 
