10 



PROBLEMS OF RELATIVE GROWTH 



In other words, if the logarithms of the magnitudes are plotted, 

 we should expect a straight line, from the slope of which the 

 value of k can be read off ; (if a be the angle the line makes 

 with the x axis, then tan a = k). Fig. 3 shows the excellent 



3.5 



I 



H3.0 



2.0 



1P 



17 2.0 



0.5 



3P 3.4 



Fig. 3. — Increase of the logarithm of absolute chela-weight with the logarithm 

 of body-weight in male fiddler-crabs. 



approximation of the actual points to a straight line when so 

 plotted. In this particular case, the constants are as follows 

 — first phase (to total weight i-i g. or just over ; rest-of-body 

 weight about 075 g.) : b = 0-0073, k = 1-62 ; second phase 

 (from this point to maximum size, in this sample maximum 



