RELATIONS TO LIGHT. 



387 



1015. Eelations of growth to light. It i.s only under the iufln- 

 enee of light that the plant can prepare from inorganic matter 



1 Text-book, 2d Eng. ed., p. 830. 



2 Warme und Pflanzensachsthum, 1870, p. 43. 



^ Biblioth^que universelle d. Geneve, Archives des Sciences physiques, 

 x.xiv., 1865, p. 243. 



* Materiaux pour la connaissance de rinflnencede la temperature sur les 

 plantes. Archives Neerlandaises, v., 1870, p. 385. 



Koppen has given an instructive table which exhibits the relations of 

 growth to temperature in a few common plants. The figures denote the growth 

 in forty-eight hours of the whole descending axis of each plantlet. 



