THE RATE OF GROWTH 115 



figures for girls also. They come up nearer to the 

 200 per cent than in Muhlmann's table, but drop 

 well below 30 per cent, in the second year, and down 

 to 20 per cent, in the fourth. Then occurs the slight 

 increase of growth in the period of twelve, thirteen, 

 fourteen years, and next the final stage of decline. 

 In the four cases the human rate curve is similar. 

 The great fall takes place at the beginning, the slow 

 fall towards the end. Professor Thoma 1 has thought 

 he could get somewhat more accurate results by 

 putting boys and girls together, and he has made a 

 calculation, as shown now upon the screen, of a curve 

 in which the two sexes are combined. His figures 

 again differ somewhat from those we have considered, 

 but you meet in this curve(Fig. 4i)alsothe same general 

 phenomena. There is an enormous percentage of 

 growth during the first year ; an enormous drop dur- 

 ing the second ; then the slow decline ; the moderate 

 fluctuation upward ; and then the last slow disappear- 

 ance of growth. In every instance, therefore, we have 

 an absolute demonstration, it seems to me, of the 

 strange phenomenon. Paradoxical it will sound, 

 whenever it is first stated to any one, that the period 

 of youth is the period of most rapid decline ; that the 

 period of old age is that in which decline is slowest. 



1 R. Thoma, Untersuchungen ueber die Grosse und das Gewicht der anaton^- 

 ischen Bestandtheile des menschlichen Korpers, Leipzig, 8vo, 1882, Tabelle 

 XXVIII.. p. 149. 



Professor Thoma gives only the usual data, the averages and first differences. 

 From them I have calculated the percentage increments, in accordance witli 

 which the curve, Fig. 40, has been constructed. Thoma's table is based on 

 Quetelet's measurements. 



