32 Journal of Entomology and Zoology 



study ol thin sections of the cord of this animal. Whethei the cells 

 actually anastomose or not is a questions hard to decide, but in 

 the numerous contacts ol naked fibers there is, 1 believe, ample 

 opportunity lor the transmission ol complex changes from cell to 

 cell, to all parts of the nervous system. In this form there is no 

 particular localization ol definite centers. 



I lie brain (.lifters in structure from the cord, the central fibrous 

 mass is more dense, the cells are very much smaller ami more 

 numerous. Some cells ol the brain send their libers out directly 

 without the common pathway o! a distinct nerve trunk. No special 

 features of the brain were determined except the cerebral organs 

 already described. 



Andreae 1882 



Beitrag zur Anatomie und Histologic des Sipunculus nudus. 

 Zeit. t. Wiss. Zool. t. xxxvi. 



Andrews, E. A. 1 SS7 



Notes on the anatomy of Sipunculus gouldii Pourt. Studies Biol. 

 Lab. J. H. univ. vol. iv. 



Delage el Herouard 1X97 



Traite de zoologique concrete. Les vermidiens. vol. v. Paris. 



Haller, B. 1889 



Beitrage zur Kcnntniss der Textur des Central nervensystem 

 Hoherer VVurmer. Arb. des Zoolog. Inst. Wien Tom. viii. 

 Heft 2. 



Marcel, A. Herubel 1907 



Recherches sur Sipunculides. Chap. iv. Le system nerveux. 

 Mem. soe. d. France, t. \\. 



Melalnikoff,S. 1900 



Zeit. Wiss. Zool. Bd. Ixviii. 



Herubel, A. 1902 



Sin- Le cerveux du Phascolosome. Ae. d. Pans, exxiv. 



Spengel,J. II'. 1912 



Beitrage zur Kenntnis der Gephyren. Zeit. Wiss. Zool. Bd. 

 xxxiv. 



Ward, 11. n. 1891 



Some points on the anatomj and lustor\ of Sipunculus nudus. 

 Bull. Mus. Comp. Zool. Harvard College. 



(Contribution from the Zoological Laboratory of Pomona College) 



