306 BRUCE F. CUMMINGS 



In my opinion, the tail vibration is simply a method of eliminat- 

 ing a surplus of nervous activity stored up, at the sexual sea- 

 son, — is without any definite purpose. The question requires 

 further analysis, however, and it is worth consideration. For 

 example, the male bends its body towards the female. This 

 movement brings the head and especially the cloaca nearer 

 the female. Supposing that the male's body is curved around 

 in that direction simply from sexual desire, it is clear that the 

 tail can be bent and vibrated most easily on the inside of this 

 curve, that is to say towards the female. No alteration in the 

 side on which the tail vibrates is made without the preliminary 

 spasm and bend of the body. Last spring, I had several ill- 

 conditioned males which, through ill health, looked superficially 

 as dull in color as females. On more than one occasion, I saw 

 a male displaying in front of these animals. Whether this 

 signifies that the female is recognized by sight alone, I cannot 

 say. The evidence is insufficient. 



