SECT, v THE NERVOUS SYSTEM 83 



origin. This difference in the position of the brain in 

 A pus and Limulus is one of those cases, referred to in 

 the preface in which the differences between these two 

 animals afford more striking proof of their relation- 

 ship, through a common origin from a bent Annelid, 

 than any similarity in the position of the brains could 

 have done. 



G 2 



