THE AXIAL ROTATION OF AQUATIC MICROORGANISMS 



AND ITS SIGNIFICANCE. 



L. B. Walton. 



Some studies concerning the axial rotation of aquatic 

 microorganisms occupying my attention during the last two 

 years, have yielded results which it is believed are of decided im- 

 portance in connection with the principles underlying evolution. 



In general it may be stated that the positively phototactic 

 free swimming forms of the northern hemisphere rotate clock- 

 wise, assuming the observer in front of the advancing organism, 

 and the negatively phototactic forms counter-clockwise, while 

 in the southern hemisphere there are reverse conditions. The 

 apparent exceptions thus far noted have been found closely 

 allied to northern forms and may have been introduced sub- 

 sequent to the origin of the southern forms. 



The evidence although far from complete is gradually 

 accumulating that the characteristic is one which has been 

 gradually impressed upon the organisms through the rotation 

 of the earth and the apparent path of the sun from east to west. 

 Any attempt to account for it on the basis of natural selection 

 can scarcely gain credence. While the possible effects of the 

 angular velocity of the earth or of certain electrical conditions 

 may be considered, it does not seem that the result could in 

 this way be explained. Experimental attempts to reverse 

 or to diminish the rapidity of the rotation of the organisms 

 have thus far failed. 



The problem is an interesting one from the geophysical as 

 well as the biological point of view, and many interesting 

 principles come under consideration. Among these may be 

 mentioned the Pendulation Theory, Bipolar Distribution, 

 The Twining of Plants, The Tropism Theory, etc. Similarly 

 the direction of the spirals in Spirochaeta, Spirulina, Arthro- 

 spira, Spirogyra, etc., are of interest. 



Modern genetics throws light on the distribution but not on 

 the origin of the character producing genes or factors. These 

 units have in general long been in existence. It is to some 

 such principle as the one suggested that we must look for 

 evidence sufficiently definite to overcome the prejudice which 

 has arisen against the old acquired character ideas as to the 

 fundamental origin of characters. 



