CHLOROPHYLL AXD THE CHLOROPLASTS 



Z77 



>NH 



O 



>N 



>NH 



Mg — O — CH 



O 



o 



>N 



>NH 



Mg — O — CH 



/ 



O 



o 



>N 



>N 



/ 



Mg — O — CH 



[ 

 \ 



>NH 



>N 

 >NH 



>N 

 >NH 



Mg — O — CH 



Mg 



O 



CH > 



O 



>N 



/ 



Mg — O — CH 



>N 

 >N 



\ 



] 



Mg HO — C — H 



>N 



>N 



/ 



Mg + HO — C — H 



Mg HO — C — H 



>N 



From these formulae it is evident that Maquenne assumes the final 

 formation of a compound containing a chain of carbon atoms, in the 

 illustration glyceric aldehyde or dioxyacetone, instead of formaldehyde. 

 The formation of a straight chain of carbon atoms would occur in the 

 chlorophyll complex, i.e., by inference, as a result of the colloidal state 

 of the chlorophyll. The theory is essentially a modification of the Baeyer 

 conception ; the primary formation of formaldehyde and the subsequent 

 condensation of this to hexose are avoided in Maquenne's conception of 

 the reaction. The assumption of an intermediate product such as formal- 

 dehyde, the proving of which has been the source of so much dispute, 

 is thus obviated. In order to conceive of the direct formation of a 

 hexose sugar, it suffices to admit the possibility of a complex of six 

 chlorophyll molecules which absorbs six molecules of carbonic acid. 



That this theory of Maquenne is highly speculative needs no comment. 

 There are many steps in the reasoning which are pure assumption or 

 based upon facts which are not well established. It is evident that the 

 whole theory rests upon the opinion that chlorophyll in the leaf is in a 



