WORK OF THE UNITED STATES DEPARTMENT, &c. 143 
Corn oR Maize HyBripisATION. 
Only very few of the numerous important problems here presented to 
the plant breeder have as yet been taken up. In the hope of securing 
better-yielding races the exceedingly large-kerneiled Cuzco, or Peruvian 
Corn recently imported into the United States by the Department of 
Agriculture, was used in hybridising with certain of our best races. 
The Hickory King, a very large-kernelled white dent, and Leaming, a 
well-known yellow dent, were used as the seed-bearing parents. The 
Cuzco, from which the pollen for the hybrids was obtained, was grown 
from kernels of a graphite colour, this colour being distinct from that of 
any race of Corn in the United States with which I am familiar. 
The current or immediate effect of pollen (xenia), so commonly 
reported as occurring in Corn, was shown in these hybrids; and although 
no check experiments were made (the work not being carried on to 
demonstrate this feature), there can nevertheless be no doubt that the 
coloration was due to the effect of the pollen. The seed of the Hickory 
King and the Leaming used was grown by careful seedsmen, and strict 
attention was given to keeping it pure and true to type. None of the 
ears except those which had been crossed showed any indication of 
impurity. Some of the kernels of the Hickory King ears crossed with 
the pollen of the Cuzco showed irregular spots of the characteristic 
graphite colour of the Cuzco, while others were entirely of a slate colour, 
these being somewhat lighter in colour than those of the typical Cuzco. 
So far as could be observed, the Cuzco used was not a fixed type, some of 
the kernels being mottled with red, olive purple, or brown. In a few 
instances the immediate effect of the pollen was apparent in Leaming 
crossed with Cuzco,* the kernels showing a peculiar admixture of the 
colours of the parents, that is of dark olive purple and the orange yellow. 
In the case of the hybrids of Hickory King with Cuzco grown from 
kernels showing the immediate effect of the pollen, which were marked 
when planted, their increased vigour, purple stalks, and whorls of anchor 
roots (inherited from the Cuzco, the male parent) showed that they were 
without question hybrids of the two races named. In the same charac- 
teristic way the influence of the male parent was evident in many of the 
hybrids from kernels in which no immediate effect of the pollen was 
shown. All hybrids showing intermediate characters were very late in 
flowering, which is another characteristic of the Cuzco, it being a tropical 
plant, and therefore requiring a long season to develop. These hybrids 
as a rule matured slightly earlier than the Cuzco plants in the same 
field. 
Other hybrids have been made with a view of securing sorts that will 
yield better in northern regions, where flint Corn, which ripens early but 
is a poor yielder, is now grown. Some of these hybrids are very 
’ promising; for instance, one of Gilman Flint (a good race of the flint 
Corn) when crossed with Leaming pollen produced ears almost twice as 
large as those produced by the Gilman Flint grown under similar con- 
ditions, there being sixteen rows of kernels on the ear instead of twelve, 
* The crosses of Leaming with Cuzco were made by Mr. E. C. Rittue, gardener 
of the Division of Vegetable Physiology and Pathology, at my request. 
