BLUE GLASS. 135 



blue glass than under yellow glass, they germin- 

 ated about equally well under colorless glass or 

 none at all. 



The effects of different kinds of light on the 

 growth of plants are very different from their 

 effects on the germinating seed. Growth consists 

 of two distinct processes; first, the absorption and 

 fixation of carbon from the air under the influence 

 of chlorophyll ; second, the transfer of this material 

 into the plant tissues, or growth proper. In the 

 Bulletin of the Botanical Society of France for 

 1886, on pages 120 and 123 of the Review, are 

 notices of two recent experiments on these sub- 

 jects; one by Bonnier and Magnin, of France, in 

 which it was shown that the chlorophylline action 

 (fixation of carbon) of the ultra violet rays is very 

 feeble; the other, by Henslow, of England, showing 

 that the rays at each end of the spectrum (red as 

 well as violet, ) were especially favorable to transpi- 

 ration. Kay, of England, had long before shown 

 that light alone caused the formation of chlorophyll. 

 The experiment of Bonnier and Magnin also goes 

 to show that in the light this action is most rapid, 

 while from the experiment of Henslow we begin to 

 understand how it is that growth, or the use of 

 the accumulated food materials in the formation of 

 the plant, is probably favored by darkness. Every 

 observing farmer will tell you how rapidly his corn 



