160 



THE RATE OF GROWTH 



[CH. 



high in a summer; the kudzu vine (Pucraria) may grow twelve inches 

 in twenty-fouE hours, and some bamboos are said to have grown 

 twenty feet in three days (Figs. 32, 33). 



10 

 Days 



Fig. 32. Growth of Lupine. After Pfeffer. 



Growth of Lupinus albus. (From G. Backman, after Pfeffer) 



In the pre-natal growth of an infant the S-shaped curve is clearly 

 seen (Fig. 18); but immediately after birth another phase begins, 

 and a third is imphcit in the spurt of growth which precedes puberty. 

 In short, it is a common thing for one wave of growth (or cycle, as 



