66 EARTHWORMS AKD THEIR ALLIES [ch. 



modern views in close contact with the terminations 

 of nerve fibres. These are furnished often at their 

 free tips with minute sensitive processes. There is 

 nothing in the structure of these to associate them 

 definitely with any sense in particular. They suggest 

 of course tactile organs more than organs of any 

 other sense. In addition to these are certain pro- 

 blematical organs which are found in the Eudrilidae 

 and are present in the members of one section of 

 that group, the section which is represented by the 

 universally found Eudrilus. 



These bodies have been compared to a Pacinian 

 body (a sense-organ found in Vertebrates) and they 

 bear no little resemblance to it. For each consists 

 of a darkly staining core surrounded by a layer 

 of cells arranged like the coats of an onion. In 

 any case it would appear that these bodies must 

 be looked upon as of a sensory nature, though they 

 do not reach the surface of the body but underlie 

 the epidermis. Their function must remain purely 

 a matter of guesswork at present, for nothing to the 

 point is known of the habits of the Eudrilidae. It 

 has been suggested by Dr Gustav Eisen that these 

 cells are auditory and serve to warn the worm of the 

 footsteps of birds and other enemies. That too is 

 his view of certain peculiar but different cells found 

 in the epidermis of Pontoscolex. In the latter some- 

 thing like an otosome has been found which is 



