68 



THE 



PART I 



prostomium giving off two pairs of nerves to the 

 two pairs of eyes, and connected by cesophageal 

 commissures with the infra-cesophageal ganglion in 

 the first segment. From this ganglion the nerves to 

 the first antennae diverge ; they may perhaps have 

 been united for some distance with the cesopha- 

 geal commissures. It is even possible that their 



FIG. 17. Diagram of the first five segments of a carnivorous Annelid to sho\y the 

 arrangement of the nervous system, from above. f>, brain ; _>, anterior pair of 

 eyes on the prostomium ; e\, posterior ditto : aj, first antennae ; a-2, antennal para- 

 podium of the second segment. 



ganglia may have moved forwards along the com- 

 missures towards the brain, as in many Annelids we 

 find the antennae moved forwards till they appear to 

 be projecting from the posterior edge of the prostomium. 

 The second antennae, belonging to the second segment, 

 would receive their nerves from the second ventral 

 ganglion, then would follow the nerves to the para- 

 podia of the third segment, &c., in order. 



