LEAVES IN SEASONS 14-9 



It is found in greatest quantity in leaves in 

 layers of special cells beneath the epidermis. 

 It is not distributed throughout the entire 

 cell, but occurs in the masses of protoplasm 

 which the botanist terms chloroplasts. The 

 chloroplasts are sponge-like structures, and 

 the chlorophyll is to be found in solution in 

 an oil in the interstices of the protoplasmic 

 sponge. 



Chlorophyll is an extremely complex sub- 

 stance and correspondingly unstable. Hence 

 as soon as the chemist extracts it from the 

 plant in the attempt to make an analysis, 

 disintegration sets in and he is no longer 

 dealing with chlorophyll, but with the sub- 

 stances derived from it by decom])osition. 

 Investigation upon the nature and activity 

 of plant-green has been in progress more than 

 a century, yet its exact chemical composition 

 is unknown. It contains carbon, oxygen, 

 hydrogen, nitrogen, magnesium and phos- 

 phorus, but the proportions and arrangement 

 of the atoms of each element in the molecule 

 of chlorophyll have not been exactly ascer- 

 tained. 



The beautiful and strikmg colors of autum- 

 nal foliage are due in greater part to sub- 

 stances formed by the disintegration of chlo- 

 rophyll. The many thousands of tints of 

 green leaves are due to a number of causes. 



