Green Leaves at Work 95 
In autumn, Nature withdraws the coloring-matter 
from the chlorophyll bodies, and at last the bodies 
themselves disintegrate, so that by time the leaf 
Fic. 17,—Some common fresh-water alge. (Much magnified.) 
a, Zygnema, with two star-shaped chlorophyll bodies in each cell; 4, Mougeotia, 
with a single oblong chlorophyll body in each cell; c, Spirogyra, with chloro- 
phyll bodies in the form of spiral bands. 
falls nothing is left of them but a few yellow 
granules. 
When a plant which has been growing in the 
light is subjected to continued darkness, the green 
pigment fades out of the chlorophyll bodies so 
that they become pallid, and finally white. Event- 
ually the little disks or ovals themselves disorgan- 
