117 



Eugene Rabinowitch 



the lipoid laj'^ers having a thickness of the order of 30-50 

 A). 



Another problem is the relationship between the layered 

 structure, as observed on chloroplast sect ions , and the 

 "cobblestone" appearance of separate lamellae when vicv/ed 

 from above. In the interpretation of the structure of mit- 

 ochondria, the layered structure has been emphasized at 

 some times, and the presence of, more or less spherical, en- 

 zymatic units, at other times. Perhaps, the lamellae in 

 chloroplasts , similarly to those in mitochondria, also bear 

 --or even themselves consist of — spherical units, perhaps 

 identical with the "photosynthet ic units," whose existence 

 was first deduced from the experiments by Emerson and Arnold 

 on photosynthesis in flashing light, and since supported by 

 many other observations. Thomas observed that for chloro- 

 plast particles to be effective in the Kill reaction, they 

 have to contain at least two layers--an observation that 

 fits into the above-derived picture. 



Pigment 

 System 2 



Pigment 

 System 1 



Fig. 3 



