58 



NERVOUS SYSTEMS AND SENSE ORGANS 



In the female the central anal ganglion is the largest. It con- 

 nects with smaller lumbar ganglia out laterally and by a loop with 

 the rectal ganglion. 



In the male the anal ganglion is large, but the two lumbar are 

 nearly as large. Two rings of nerves are connected with the anal 

 ganglion and one with the small cloacal, and the other with the 

 rectal ganglion. 



GORDIODEA. Villott, 1874, shows that the ventral cord repre- 

 sents the central nervous system with an anterior and posterior 





m 



iwm 



Fig. 17. A-F. Nervous system of Goidoidea. A. Section through brain and 

 suboesophegeal band, much changed from Montgomery. B. Position 

 of supra and suboesophageal ganglion modified from Montgomery. 

 C. and D. Sections of ventral cord. E. and F. Cross and longitudinal 

 sections of the ventral cord after May. G and H. Head of Chaetog 

 >wfha after Hertwig, showing brain, sense organs and chief nerves. 

 I. Ventral ganglion shown, Hertwig. .J. Eye of Chactngvntha. K. 

 Ganglion in body of Acni'h^ii-i'phalia after Leuchart. 



ganglion. In 1887 he traced fibers from the head ganglion into the 

 thickened hyrodermis of the head. Vejdovsky. 1883, 1894, con- 

 siders that there is no cerebral ganglion and no ganglion cells on 

 the dorsal side of the peripharyngeal ganglion. He distinguishes 

 neuroglia cells. 



