Solomon'0 IRtvals 103 



the predecessor of the leaf-green, and changes to 

 leaf-green by light and Avarmth. To maintain this 

 leaf-green the plant must have j)lenty of carbonic 

 acid gas, and but little oxygen. 



Here is another curious fact : When leaf-green is 

 taken from the leaf and compressed and freed as far 

 as possible from other substances by chemical treat- 

 ment, if it is made into a thick layer and looked at 

 upon the surface, it aj^pears of a deep lake red. Make 

 the layer thin and look through it, and it is of a rich 

 green. 



A plant naturally having green leaves cannot pre- 

 pare proper food stuff without leaf-green. If it is 

 robbed of this chlorophyl by darkness and cold, no 

 food will be prepared in the leaves, and the plant 

 will soon starve to death under the insufficient feed- 

 ing of the root. 



Some ferns have been known to take on leaf-green 

 if they had plenty of warmth while in darkness. 

 This suggests that the change from etiolin to chlo- 

 rophyl is in part a cooking process. In j^lants 

 where leaves and stems^'e bj'' natnre~gaytyT^olored, 

 the work of the leaf-green is performed by the soft, 

 brightly-colored pulp which takes its place. 



When plants become parasitic and suck out of 

 other plants the leaf-prepared plant-food, they cease 

 to use their own leaves, and these leaves turn into. 



