Chapter XI — 121 — Role of Chondriosomes 



there exist phenolic compounds (tannins, oxyflavanol and antho- 

 cyanin pigments) capable of reducing silver nitrate. Moreover 

 this reagent is never reduced by the leucoplasts, the chromoplasts, 

 or the chondriosomes in tissue which is, nevertheless, rich in 

 ascorbic acid but lacking in chloroplasts and there is reason to be- 

 lieve that ascorbic acid is localized in the vacuoles. Mirimanoff 

 thinks that the Molisch reaction has a totally different significance 

 from that attributed to it by GiROUD. He thinks that it may be 

 compared to a photolysis, the activator being chlorophyll, the 

 hydrogen donator, glucose. 



In addition, it has been supposed that the chondriosomes and 

 plastids are chemical catalysts. From this point of view a first 

 hypothesis was formulated by Nageotte to explain both the role 

 of the genuine chondriosomes and that of the plastids of green 

 plants. It is based on research in plant cytology which has dem- 

 onstrated that the plastids, regarded as a special category of 

 chondriosomes, are not destroyed during their operations, and it 

 attributes to chondriosomes and plastids the role of heterogeneous 

 catalysts. The homogeneous catalysts according to this theory are 

 represented in the cytoplasm by the diastases and the heterogeneous 

 catalysts by the chondriosomes and plastids. 



Devaux later formulated a different hypothesis, according to 

 which the role of catalyst is played by the interfaces between the 

 chondriome and the cytoplasm. Devaux formulated an interesting 

 suggestion which gives significance to the heterogeneous structure 

 of the cell and brings out its real importance. He demonstrated 

 that all solid parts of the cell are orientated molecularly. Each 

 molecule or elementary particle not only occupies there a definite, 

 but an oriented, position. All the poles of like affinities occupy 

 one face of the membrane while all the opposite poles occupy the 

 other face. These facts made it possible for him to conclude that 

 the plasmic membranes in particular must constitute the principal 

 tools of the protoplasm. Applying these data to facts brought out 

 by cytologists, Devaux, in order to explain the prodigious work 

 which goes on in the cell, alleges surface actions which may be 

 reduced to, or classified as, the operations of surfaces in the proto- 

 plasm. Now all protoplasmic surface, external or internal, is 

 characterised by the formation of a coagulation membrane. The 

 polarized (catalytic) membranes are the scene of cellular activities 

 (activation by surface agency). There is a catalytic localization 

 of protoplasmic activity on the surfaces presented by the pro- 

 toplasm: between the cytoplasm on the one hand, and the nucleus, 

 chondriosomes, plastids, vacuoles and cellular membrane on the 

 other. 



This hypothesis is based on the fact recognized by Otto War- 

 burg, that, in the eggs of the sea urchin, respiration takes place 

 essentially all along the protoplasmic membrane. Warburg ap- 

 plied this notion to the chloroplasts, whose activity he considers 

 to be purely a surface activity. Devaux says, "It must be con- 

 cluded that the cell is a system of numerous catalysts in the form 



