330 



EVOLUTION, GENETICS, AND EUGENICS 



In short, according to Klebs, in comparison with normal white Hght, 

 the production of organic substances, such as starch and sugar, is 



TABLE I 



Chemical Composition of Three Plants of Scdum Spectabile Grown in 



White, Red, and Blue Light 



Substance 



Ash 



Sugar 



Calcium malate. 

 Free nitrogen. . . 



Starch 



Crude protein . . 



White 



13.20 

 II .04 



22 

 o 

 5 

 5 



29 

 16 

 82 



3i 



Red 



13.20 

 15-40 

 18.02 



0.33 

 3.66 

 6. IS 



Blue 



18.60 



2.40 



iS.io 



0-59 

 1 . 20 

 7.64 



diminished under the influence of blue light as microchemical and 

 macrochemical tests distinctly show. In consequence of this dimin- 

 ished assimilation of carbon dioxide the rosettes become purely 



Fig. 52. — -Above the diurnal peacock butterfly (Vanessa io), and below, forms 

 produced by subjecting the pupae to unusual temperatures. (From Babcock and 



Clausen, after Goldschmidt.) 



vegetative. In red light the carbon assimilation is greater than in 

 blue light but less than in white. These experiments prove that the 

 transformation of a plant "ripe to flower" into a vegetative one 



