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EDGAR NELSON TRANSEAU 
that the length of the vegetative cycle is an inverse function of the 
specific surface of the cells. This may be explainable on the basis 
that the processes of absorption, photosynthesis, pro teinsyn thesis, 
and assimilation are limited by the cell surface, while the capacity 
for accumulation is limited by the volume. Hence other conditions 
being equal in the cells with the largest specific surfaces we might 
expect the most rapid approach to maturity (Fig. 2). It has been 
shown that plant processes are accelerated by temperature, being 
^5 
Fig. 3. Curve for the three variables: specific surface, temperature, and time to 
fruiting. 
doubled by a rise of ten degrees. Since the temperature gradually 
rises during this period a correction must accordingly be made. Near- 
ly all the species germinate in March and for those that fruit in about 
thirty days the average temperature is about 5° C. For those that 
fruit in July the average temperature of the whole vegetative cycle 
is about 12° C. We have then three variables the lengths of the 
vegetative period, the specific surfaces, and the temperatures. The 
interrelations of these three variables may be represented by the 
empirical formula 
(J — 
10 
