CHLOROPHYLL. 



51 



66. With few exceptions chlorophyll is not found in cells 

 which are not exposed to the action of light.* When ordi- 

 nary green plants are removed for some time from the light, 

 the chlorophyll disappears from the chlorophyll-bodies, and 

 leaves them colorless. The same decoloration also takes 

 place when a plant is deprived of 

 iron as one of the constituents of 

 its food. The disappearance of 

 chlorophyll takes place normally in 

 higher plants when the cells lose 

 their activity. In the case of leaf- 

 cells, upon the approach of autumn 

 the chlorophyll appears to be re- 

 moved to other portions of the 

 plant. 



(a) The cells of many Palmellacere, 

 and many swarm-spores e.g., of (Edogo- 

 nium and Vaucheria furnish good ex- 

 amples of the coloration of nearly the 

 whole body of protoplasm. 



In Zygnema th'j chlorophyll-bodies are 



stellatu, and in Spiroyyr,', spiral. 

 In Vaucheria there are multitudes of 



roundish or slightly angular clilorophyll- 



bodies, which line the interior of the 



large cells. The chlorophyll in the 



leaves of many mosses may be easily 



studied, even without making- sections ; 



in them the chlorophyll-bodies are round- 

 ish in outline. In the higher plants thin 



cross-sections of the leaves afford the 



best means for the examination of their pjg 43. Two filaments of Spl- 



longata ; the chlorophyll 

 iral bands ; in the centre 

 . cell is a nucleus, with 



(b) Chlorophyll is soluble in alcohol, x^^VtSch?' protoplasm - 

 ether, chloroform, benzine, essential and 



fatty oils, hydrochloric and sulphuric acids, and these may be used 



* The cotyledons of many Coniferae acquire a green color even in 

 total darkness. The embryo of Phoradendron is green in the unopened 

 seed, and in certain seeds with thick coats, which are impervious to 

 light (e. g., in some (Jucurbitdceae), a chlorophyll -bearing layer of cells 

 surrounds the embryo. 



chlorophyll-bodies, which are uniformly ro,jyra longata : the chlorophyll 



... , , .. is in epiral bands ; 111 the centre 



of a simple rounded outline. of eacu ce ii \ 6 a nucleus, with 



