144 



PROBLEMS OF RELATIVE GROWTH 



period, since he believes that he has established in his earlier 

 papers the fact that during development, growth-rate sinks 

 in simple inverse ratio to time. 



8 10 12 14 16 18 20 22 24 26 28 30 32 34 36mm. 



4 6 8/0/2/4 16 18 20 22 24 26 28 30 32 34 36 mm 



A 

 Fig. 73. — Weight-growth of various organs in the embryo chick, plotted on 

 growth-rate, A, against age as determined by increase of v'embryo volume 



various organs are indicated in the legend. In 

 In A, x is weight of lens ; and + (continued to the right and below) weight of fore-limb. In 

 the portions of development shown the lens increases from 8 x 10- 6 g. to 0-0088 mg. ; the fore-limb 

 from 7-5 X 10- 4 g. to 0-54 mg. ; the embryo from 0-87 to 41 g. 



{Constructed from the data of Schmalhausen, 1927A, Tables 9, 15, 18 ; 1927B, Table 7. 



