Pomona College, Claremont, California 



79 



degenerate or else for some other purpose. I he ganglia arc con- 

 nected by their perineuria] sheaths in the mid line and the nuchal 

 sacks, though they do not I use arc separated merely by a thin 

 septum. rhey differ in tins respect from Lumbriconereis erecta 

 Moore where the ganglia are quite widely separate. 1 [istologically 

 the structure is much the same as the other ganglia ol this form. 

 The cells are a little larger than those oi the brain and the reticulum 

 is considerably more noticeable. 



The subcesophageal ganglion (Fig. 1 ; }) is ol the usual annelid 

 form as is the nerve trunk ( Figs. S, 9). The segmental nerves are 

 given oil <»ne pair to each segment from a long narrow pedicle 

 { lie;. 3;k). 1 hey follow around the segment just outside the mus- 

 cular coat. At the base ol the loot there is a small ganglion giving 

 oil two branches, owe to the loot, which branches twice and one 

 passing beyond the toot to the dorsum where it branches extensively 

 in both the epithelium ami muscles. 



Visceral System. 1 he visceral nervous system (Fig. 4), con- 

 sists ol three visceral ganglia, ami a complex system ol nerves serv- 

 1 1 1 i_^ the various pharyngeal muscles. The system originates in a 

 mam visceral ganglion ( Fig. 4; v). which is situated just below the 

 brain and is equipped with lour pairs ol symmetrical brandies. 

 The front pair ol nerve trunks are short ami rather thick. They 

 lead to the lateral halves ol the brain and their fiber masses fuse 

 with the "punkt-substanz" ol this part ol the brain. The side 

 branches leave the visceral ganglion at about its central and widesl 

 part and lead to the base ol the oesophageal connectives. Near 

 where these nerves leave the viscera] ganglion a pair ol small nerves 

 (Fig. 4; r) about .01 mm. in diameter branch oil from the ventral 

 side and extend eaudad lor a distance ol about 2.5 mm. These 

 nerves form an analogue ol the complex labio-visceral nervous svs- 

 tem found in Eunice. (Quatrefages; '44.) The two hind trunks 

 branch out into the visceral nervous system proper, as diagrammed 

 (Fig. 4). rhey go straight back, parallel, assuming a diameter of 

 about .04 mm. About 1 mm. behind the \ isceral ganglion they 

 branch into an outer (Fig. 4;m) and an inner pair (Fig. 4;u). 



I he outer pair form the maxillary nervous system. They bend 

 ventrad and branch in a very complex manner on either side ol the 



