THE BEHAVIOR OF MITOCHONDRIA 49 



gland was extirpated, and the effects on the mitochondria 

 noted in the remaining portion of the gland which pre- 

 sumably was called upon to increase its activity. The 

 mitochondria were examined at various periods after the 

 operations. It was found that they had not altered in 

 morphology, but had increased considerably in numbers. 

 Nicholson also tested the effects of various gases and chemi- 

 cals. In some instances the mitochondria exhibited pleo- 

 morphism. 



The investigations of Bowen ('19-'22) and others, on the 

 behavior of mitochondria in spermatogenesis have brought 

 to Ught some interesting activities of the mitochondria of 

 germ cells. It has been shown that the mitochondria in 

 the male germ cells of certain insects come together and 

 fuse into a single body, the nebenkern. This body is not 

 homogeneous in structure, but is composed of at least two 

 distinct materials which Bowen was able to distinguish by 

 means of staining reactions. In later spermatogenetic 

 activity, the nebenkern becomes pecuharly laminated. 



These activities, that have been so clearly described and 

 illustrated by Bowen, appear, on first analysis, to be quite 

 unrelated to any comparable process in the bacteria. 

 Lohnis, in his monograph on the "Life Cycles of Bacteria," 

 however, has described and illustrated processes that are 

 identical with the early changes described by Bowen. 

 According to the conclusions of Lohnis which are based 

 not only upon his own observations, but also correlated with 

 those of many other investigators, bacteria possess a life 

 cycle. One step in the process consists of the fusion of a 

 number of bacteria into an amorphous mass which Lohnis 

 has named the "symplasm." Later, individual bacteria 

 become separated from this mass or symplasm, and again 

 become independent organisms. WTiile many bacteri- 

 ologists have not accepted this work of Lohnis, I know of no 

 definite evidence against it. 



