175 



The Effect of Centrifugal Force on Plants. 



F. M. Andrews— Indiana University. 



The effect of the successive displacement of contents in plant cells 

 has never been carried out to the full extent. This would be an inter- 

 esting piece of research in as much as it would show not only the 

 capacity of plant cells to resist possible injury by repeated displace- 

 ment of the contents over long periods, but also that it would demon- 

 strate the recuperative power of such cells. Especially if this latter 

 began to diminsh it would be important to know when and how rapidly 

 the protoplasm reacted in this respect. I have already performed a few 

 experiments of this kind where, however, the contents of Closterium 

 moniliferum was displaced only a few times successively.' Approxi- 

 mately no difference was noticed in this plant when centrifuged suc- 

 cessively a few times and the specimens kept in the dark. 



I have more recently tried the same experiments on Oedogonium 

 ciliatum with similar results. The following four experiments will show 

 the response of the plant when centrifuged 15 minutes at 26 °C. I cen- 

 trifuged Oedogonium ciliatum, using 1,500 gravities. All the contents 

 were displaced which returned in the light in 7 days. After the second 

 centrifuging the contents returned in 6% days. After the third centri- 

 fuging in 6 days and after the fourth centrifuging in 6% days. Clearly, 

 from these few experiments, the protoplasm is apparently not detri- 

 mentally affected and shows that a large number of such experiments 

 would be necessary to determine this point. There are interesting ques- 

 tions to be ascertained in such experiments, among them being that of 

 the response of the protoplasm to certain stimuli when the contents are 

 displaced. 



^ Jarbiicher fiir wissenschaftlichen Botanik. 1915, Vol. 56, pp. 229-23.3. 



