Published online by Cambridge University Press: 27 March 2009
Some interesting contributions to this subject have appeared during the past three years. They contain somewhat discordant ideas and it has therefore been concluded that the present time is suitable for a brief review of the whole matter and for the publication of further experimental results. A striking susceptibility to environmental change is evinced by both the awn and the lateral floret, and it is part of the purpose of this paper to describe the nature of the fluctuations involved and to indicate the extent to which they militate against the reliable determination of genetic ratios.