574 'l'ransactions. 
Авт. 42.—Natural Self- fertilization of Wheat on a Large Scale. 
By Е. W. Hizcenvorr, M.A., D.Sc., F.N.Z.Inst. 
[Read before the Canterbury Philosophical Institute, 7th December, 1921; received by 
Editor, 20th December, 1921 ; issued separately, 22nd May, 1923.] 
THE area devoted to selection of pure strains of wheats at Lincoln College 
covered, in 1920, about 22 acres. Among these were six plots each about 
half an acre in extent, occupied by three pure strains of the variety known 
in New Zealand as White Straw Tuscan, a wheat closely allied to or identical 
with the Bellevue de Talavera of Europe. It is an early-maturing variety, 
coming into flower and ripening about a fortnight before the other 
varieties commonly grown. 
. In January, 1921, when tliey were nearly ready to cut, the plots were 
gone through for the purpose of picking out accidental impurities, this 
work embracing the roguing of intruding varieties, and in addition the 
roguing of any intruding strains of the same variety. It was at this stage 
that the fact became obvious that these three strains, G2, F8, and F10, 
were no longer pure, but included many strains—so many that it was not 
only impossible to pick out all the impurities, but, in one case, to tell which 
was the strain intended to be occupying the plot. It was at first thought 
that this was the result of accidental admixture of strains during the 
preceding harvest, where some ten Tuscan strains were grown side b 
side in the same field. But reflection on the care with which the harvest 
and there were no marked impurities in their offspring in the succeeding 
year. It was taken as an hypothesis that the frost of December, 1919, 
gh to kill the anthers of certain of the florets, 
but to leave the ovaries uninjured, so that if those ovaries developed at 
all they would have to be cross-fertilized, and that chiefly with pollen 
from their own or neighbouring strains of Tuscan, this being the only variety 
freely in flower within a fortnight of the time of the frost. 
There were three ways of testing this hypothesis :— 
(1.) To examine the mixed strains and see if their differences were such 
as to suggest cross-pollination between two strains of the same variety. 
plant. As a matter of observation, there were apparently some ӨЕ 
eight types in each of the plots, which would agree with the expectation 
