Guilliermond - Atkinson 



120 — 



Cytoplasm 



and GiROUD have maintained that glutathione is found in the chon- 

 driosomes. Joyet-Lavergne reports having locaHzed vitamin A 

 in the chondriosomes and in the plastids, but he does not seem to 

 have brought forward sufficient proofs for this localization. He 

 even reports having proved by means of certain reagents that the 

 oxidation-reduction capacity of the chondriosomes in the Sapro- 

 legniaceae depends on the presence of this substance in the sub- 

 stratum. As a matter of fact, the reactions used to detect the 

 presence of glutathione in cells are not such as to permit it to be 

 localized in the cytoplasm with any accuracy. At the present time 

 there do not seem to be any microchemical reagents which can 

 localize glutathione in the chondriosomes and the hypothesis of 

 Joyet-Lavergne has not been verified. In fact, we shall see that 



the chondriosomes do not seem to have of 

 themselves any reducing power. In any case, 

 they are incapable of reducing Janus green 

 to its leucoderivative, contrary to what has 

 been thought up to now. As for the oxidizing 

 role of these elements, it has not been con- 

 firmed either. 



GiROUD and his collaborator report having 

 localized ascorbic acid, also, within the chon- 

 driosomes of animal cells by using an acid 

 solution of silver nitrate. These investigators 

 moreover, attributed the Molisch reaction 

 (pp. 54, 104) which characterizes the chloro- 

 plasts and which they obtained by the same 

 reagent, to the presence of ascorbic acid in 

 the chloroplasts which are thus reported to be 

 the locus of this substance. To verify this 

 hypothesis, GiROUD and his collaborators 

 measured the quantities of ascorbic acid 

 present in a great number of plants, and 

 found an evident relation between the pres- 

 ence of chlorophyll and that of ascorbic acid. 

 This conception, accepted by various investigators, Mirimanofp 

 was not able to confirm in his recent research. By measuring in 

 the organs of a rather large number of plants, very accurate quan- 

 tities of ascorbic acid, he was not able to obtain any direct relation 

 in these plants between the content of ascorbic acid and that of 

 chlorophyll. There are organs, totally deprived of chlorophyll, 

 which are nevertheless very rich in ascorbic acid and, conversely, 

 there are those poor in the acid which enclose a great deal of 

 chlorophyll. If sometimes a relation is found between the presence 

 of chlorophyll in the plastids and their richness in ascorbic acid, 

 this is, consequently, only indirect and can be explained only by 

 saying that ascorbic acid, like many other substances manufac- 

 tured in plants, is an indirect product of photosynthesis. More- 

 over, MiRiMANOFF has shown that the reaction used by GiROUD is 

 not specific for ascorbic acid in plants in which very frequently 



Fig. 81. — Fixed and 

 stained cells of lupin 

 nodules. 1, bacteria re- 

 sembling chondriosomes. 

 2, 3, cell centrifuged 

 before fixing and stain- 

 ing; bacteria, heavier 

 than cytoplasm, left at 

 one side. (After MiLO- 



VIDOV). 



