Changes in number of coleoptile tillers, plant height, leaves per plant, degree of vernalization, cold tolerance (LT50) and several measurements made on the plant crown were determined for winter rye (Secale cereale L.) and winter wheat (Triticum aestivum L.) cultivars grown under field conditions in the fall of 1972 and 1973 at Saskatoon. Measurements made on the crown included fresh weight, dry weight, water content, depth, root number, root length and number of tillers. Years, dates of seeding and time of sampling had a significant influence on most variables. Correlations based on developmental differences for the acclimation period were significant for all variables measured. Dry weight was most closely related to LT50, and regression analyses indicated that the remaining variables did not explain any additional variability in LT50. Cultivar differences were apparent for most variables studied; however, these differences often did not reflect differences in field survival potential.