LIBRARY 

 NEW YORK 



PROCEEDINGS botanical 



GARDEN. 



OF THK 



Delaware County Institute of Science 



Vol. IV, No. 4 July, 1909 



THE SLUGGISH DIATOM. 



BY T. CHALK LRY PALMER. 



Various considerations have been advanced in these pages 

 for the purpose of showing how far theories of osmosis and 

 the like are from being in accord with the particulars of the 

 phenomena of diatom locomotion. The moment such theories 

 become precise enough for examination, that moment thej- 

 reveal themselves as untenable. As for osmosis, one is 

 inclined to dismiss it, once for all, with the vivacious dictum 

 of Pelletan : — "This explanation has one great fault: i1 

 explains nothing. ' Osmotic currents ' is merely an expres- 

 sion wherewith to content oneself without being obliged to 

 seek for anything further. Many authors, feeling how incom- 

 plete this pretended explanation is, have sought to study 

 more thoroughly the movements of the diatoms '■" ''^ * * 

 in order to arrive at an explanation that explains." 



Now as this study has progressed, it has been increasingly 

 evident that there is nothing special in these movements, 

 except the actual physical mechanism. Protoplasmic effort, 

 here as elsewhere, results in uKjlion. and is accompanied by 

 the phenomena that usually go with expenditure of energy. 

 The diatom is nut passive, but energetic. It is energetic in 

 the same sense that a spermatozoid is energetic, and it is not 

 p'assive as a green leaf is passive while storing up starch in 

 the sunlight and swaxiug idl\- in the breeze. 



