150 THE SHORTER SCIENTIFIC PAPERS 



experiments have been made in attempts to obtain some 

 definite evidence as to the cause of the rotation. Obvi- 

 ously it would be of interest to maintain a culture of 

 northern forms in the southern hemisphere or a culture 

 of southern forms in the northern hemisphere. Efforts 

 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 

 having a clockwise rotation of fifteen minutes was pro- 

 cured, 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 en- 

 tirely in the experiments, inasmuch as it would apparently 

 be impossible to change the direction of rotation in forms 

 like Euglena spirogyra Ehrenb., Phacus pyruin (Ehrenb.), 

 etc., where the strise are carinate in structure with an 

 angle almost if not entirely precluding a rotation in the 

 direction opposite to that in which they were accustomed 

 to turn. 



While there has been a large amount of data obtained, 

 thus far no evidence shows that either a "reversal" or a 

 "slowing up" of the rotation may be produced in any of 

 the individuals utilized. 



Even though it may not be possible to change the direc- 

 tion or the period of rotation in "adult" forms, may not 

 such changes be produced in encysted forms or during a 

 period when gametes are developed. Experiments are 

 yet to be made with individuals in an encysted condition, 

 and with material available it will be possible to utilize 

 gamete-producing forms. That Euglena has a sexual 

 cycle was pointed out by the writer nearly ten years ago 

 (Walton, 1909) .^ Certain forms encyst, the cysts subdi- 



^Paper presented at annual meeting of Ohio Academy of Science, 1908. 



