68 



THE SYNTHESIS OF CARBOHYDRATES 



molecular oxygen without the formation of hydrogen peroxide, 

 and the carbon chain, formula IV., is disengaged and thus 

 regenerates the original colloidal chlorophyll complex III. 

 The number of carbon atoms in the carbohydrate formed will 

 be the same as the number of magnesium atoms in the col- 

 loidal chlorophyll micelle : the process, therefore, does not 

 involve the formation of any intermediate substance, such 

 as formaldehyde, between the carbon dioxide and the final 

 carbohydrate. 



>NH 



O 



>NH 



>NH 



J 



>NH 



Mg-O-C-OH 



Mg-O-CH'' 



O 



>n/| 



Mg-O-C-OH 



O 



II 

 Mg-O-C-OH 



>N 

 >NH 



nt/ 



Mg-0-CH< 



>N 



-O 



I 



o 

 ,o 



' I 



o 

 ,o 



/Mg 

 r/ 



HO-CH+0 2 



>N\, 

 >N 



>N 



>N /Mg + HO-CH+O, 



>N 



>n/| 



Mg-O-CH^ 

 II 



/ 



>N 



III 



Mg HO-CH+O, 



I 



IV 



Much physiological evidence is required before this in- 

 genious speculation can be accepted ; one point, and that 

 essential, only will here be made : the thesis is founded on the 

 colloidal state of chlorophyll, a foundation which, from the 

 work of Stern * and Noack, + is not certain. 



Ber. deut. bot. Ges.," 1920, 38, 28 ; " Zeit. bot.," 1921, 



* Stern 

 I3> 193- 



t Noack : "' Biochem. Zeit.," 1927, 183, 135, 153. 



FURTHER REFERENCES. 



Stiles : " Photosynthesis," London, 1925. 

 Spoehr: "Photosynthesis," New York, 1926. 



