Remarks

Both series of statistical analyses demonstrate clearly that increasing numbers of gonangia, etc., are formed with decreasing temperature. Both series suggest (a) that in summer the production of gonangia, terminal buds and branches will fall to zero (Figs. 2-5), and (b) that temperature is a major factor in determining the trends of seasonal growth expressed by the erect stem (in terms of percentage of variability explained). Analysis by simple graphic relationship also demonstrates that great variation can occur in the percentage of stems possessing gonangia, terminal buds and branches within the weekly or monthly sampling period. Furthermore, this simple analysis suggests a critical temperature at which fluctuations in growth may take place. By critical temperature in this context, we mean that temperature above 13°C e.g., (Fig. 3) could either reduce or prohibit formation of gonangia or terminal buds. Temperatures above 11.5°C, e.g., (Fig 4) could either reduce or prohibit the formation of branches in the axil of the hydranth pedicel.

The annual range of morphology of the erect stem, described below, indicates however, that the relationship between stem growth and temperature is more complicated than is suggested by the results obtained from the autumn-winter seasons alone.