538 THE AMERICAN NATURALIST [Vol. LII 



to obtain living cultures from desirable localities, the 

 Falkland Islands, New South Wales, the southern part of 

 South America, etc., have thus far failed. A method, 

 however, was devised by which it seemed theoretically 

 possible to subject northern flagellates to an environment 

 similar to that of the southern hemisphere. A clinostat 

 (Fig. 3) having a clockwise rotation of fifteen minutes 



was procured, a circular table ten inches in diameter 

 fitted to this, and the northern half covered so that the 

 revolving table containing slides in excavated recesses 

 would pass into darkness on one side and emerge moving 

 from east to west. Thus the apparent path of the sun 

 so far as the organisms were concerned would be from 

 west to east. The larger unstriated Euglena have been 

 used almost entirely in the experiments, inasmuch as it 

 would apparently be impossible to change the direction 

 of rotation in forms like Euglena spirogyra Ehrenb., 

 Phacus pyrum (Ehrenb.), etc., where the stria? are cari- 

 nate in structure with an angle almost if not entirely pre- 

 cluding a rotation in the direction opposite to that in 

 which they were accustomed to turn. 



