THE BEHAVIOR OF MITOCHONDRIA 51 



tiire experiments, however, were not again observed, that 

 is, the production of a definite size of organism in a given 

 hydrogen-ion concentration of the medium. The results 

 that were obtained in the later subculture experiments, 

 however, appear to be more significant in relation to the 

 known behavior of mitochondria as indicated by the experi- 

 ments of the investigators quoted above. 



Plate III is a reproduction of the protocol of a subculture 

 experiment. The character of the organisms that developed 

 in each subculture is shown by means of the camera lucida 

 drawing at the right. The initial growth from which these 

 subcultures were made consisted of a pure culture of cocci, 

 represented in the upper part of the plate. The original 

 smear of the initial growth was carefully searched, but the 

 only type of organisms that could be seen were single cocci. 

 A study of this protocol reveals the pecuHar and dehcate 

 pleomorphic response of cultured mitochondria to shght 

 variations in the culture media. Another feature of their 

 behavior is represented by the drawings illustrating con- 

 ditions observed April 1, 1924. The first vertical column 

 of drawings was made from smears obtained twenty-four 

 hours after subculturing. The second vertical column 

 represents the same subcultures after incubating for twenty 

 days. In many instances, it is evident that the organisms 

 underwent a second pleomorphism during the ageing of the 

 medium. In another set of experiments, the hydrogen-ion 

 concentration of the medium was determined after the 

 organisms had shown a similar second pleomorphism, and 

 it was found that it had changed from an original pH 7.5 

 to pH 8.8. 



The subcultures illustrated at the bottom of the plate 

 imder date of March 13, 1924, also show an interesting 

 reaction. The subcultured organisms of 0^^5, which were 

 almost wholly diplococci, were again transplanted after two 

 days into the original kind of medium — nutrient agar. The 



