CEREBRAL HOMOLOGIES. 



47 



I gladly, however, welcome the authority of the indefati- 

 gable Dissector of the Molliisca in predicating corresponding 

 parts of the nervous centres in the whole series of brain- 

 possessing animals, so far as Cuvier felt himself justified 

 to go. And I avail myself of this concordance to define, 

 agreeably with our common views, the aspects of the body 

 in the adult Cephalopod, but in the terms which have 

 been suggested by conclusions as to the essential con- 

 ditions and wide extent of a possible predication of neural 

 homologies. 



The side of the body of a Cuttlefish or Squid denoted by 

 the " neuroesophageal " suboesophageal " so called) brain- 

 part, with the chief nervous extensions therefrom along the 

 trunk, is the " neural aspect," its superficies the " neural 

 surface " (fig. 9, n). The side of the body to which the 

 " hsemoesophageal " (so-called " supraoesophageal ") brain- 

 part has been turned by the course of the gullet is the 

 " hsemal aspect its superficies is the "haemal surface" 

 (ib. h). The " narrow space enclosed by the arms, which 

 contains the mouth," together with the entire acetabular 

 surface of those cephalic arms, is the anterior or " oral surface " 

 (ib. a), answering to that so termed in all other Invertebrates, 

 as is the homologous part in all Vertebrates. The opposite 

 end of the body, with its appended fins, is the posterior or 

 caudal end ; what is usually called the upper surface in adult 

 Cephalopods, as in all lower Mollusks and in Articulates, is 

 the " haemal one the opposite surface is the " neural " one. 

 As here defined and illustrated, there can be at least no 

 doubt as to the answerable aspects and surfaces in any In- 

 vertebrate possessing comparable centres and cords of the 

 nervous system, with comparable centres, or hearts, of the 

 vascular system. So the heart in man indicates the " haemal " 

 aspect (fig. 10, h), the myelon (/) the neural " aspect (ib. 



