1. The effect of low-temperature treatment on some varieties of wheat, barley and oats has been found to be profoundly affected by the time of sowing of the treated grain.

2. Winter sowing showed the least vernalisation effect, while in the spring the stimulative action became more pronounced as far as earing acceleration is concerned, as the sowing was made progressively later. This was particularly marked in winter varieties.

3. Developmental studies of the control and vernalised plants showed the stimulative action on early growth and growing point development in the winter varieties.

4. Tiller counts on control and vernalised plants of three winter wheat varieties demonstrated the fact that each variety was stimulated to earlier tiller production, but in two of the varieties this resulted in a reduction of surviving ears at harvest.