CHONDRIOSOMES 89 



out that they are best fixed by oxidizing agents depending for their effect 

 on reducing substances, probably the lipidal chondriosomes, in the cyto- 

 plasm. The chemical fitness of chondriosomes for processes involving 

 oxidation and reduction was further emphasized by the work of Mayer, 

 Rathery, and Schaeffer (1914), who also pointed out that various reagents 

 which diminish respiratory oxidations attack lipides. Joyet-Lavergne 

 (1928) reports that chondriosomes give a positive test for glutathione, 

 which is thought to be of special importance in cell oxidations and 

 reductions (probably because of a respiratory ferment associated with it, 

 according to Warburg). The observations of E. V. Cowdry on the action 

 of vital dyes are also in harmony with the respiration theory. Evidence 

 regarded as unfavorable has been brought forward by Kropp and May 

 (1924), who find that the chondriosomes in the white blood cells of 

 animals made to inhale oxygen, carbon dioxide, and ether differ in no 

 discernible way (Janus-green method) from those of normally respiring 

 animals. 



A theory that chondriosomes are the site of enzymatic syntheses has 

 been put forward by Marston (1923, 1926), w^ho finds evidence that they 

 contain proteolytic enzymes and that protein synthesis in vitro is acceler- 

 ated by colloidal lipides. Such synthesis would be greatly facilitated by 

 adsorption in the extensive interface between the chondriosomes and the 

 cytoplasm (Cowdry, 19266). The enzyme theory is supported by Horn- 

 ing (1926, 1927afo, 1928a), who observes their adherence to food particles 

 in the Protozoa and their disappearance as the food is digested. 



One of the most striking views regarding chondriosomes is that they 

 are microorganisms. Altmann (1890) thought many years ago that 

 protoplasm was essentially a vast colony of living "bioblasts" in a 

 non-living ground substance. Recently Portier (1917, 1918) and Wallin 

 (1922-1927) have independently suggested that ''mitochondria are, in 

 reality, bacterial organisms, symbiotically combined with the tissues of 

 higher organisms." Wallin finds evidence for this view in the fact that 

 bacteria and chondriosomes show certain similarities in form, staining 

 reaction, chemical composition, physical properties, and activity, and in 

 peculiarities in the development of Bacillus r'adicicola in the cells of the 

 clover nodule. Assuming that chondriosomes develop into plastids, 

 Wallin suggests further that chloroplasts are not organs developed in the 

 cytoplasm, but chlorophyll-forming organisms that have invaded proto- 

 plasm, with which they live in a state of complete symbiosis.-^ 



This bacterial theory has been severely criticized. ^^ Cowdry has 

 shown that chondriosomes and bacteria simultaneously present in the 



" See in this connection Pascher (19295) on endosymbiosis by blue-green algse. 



26Regaud (1919), Guilliermond (1919c), Cowdry and Olitsky (1922), Cowdry 

 (1923a, 1924o), Nicholson (1923), Bowen (1923a), Horning (19276), Milovidov 

 (19286). 



