174 Journal of Entomology and Zoology 
7. The close application of the deep strands to the siipertieial 
gives the appearance of dorsal and ventral cells in the ganglia of 
segmented animals. The suggestion of a dorsal sensory part and a 
ventral motor has interest if not importance in this connection. 
8. -\ simple condition of relationship of ner\e cells to each 
other seems e\ident in the radial and circumoral strands ot this 
form as well as in starfish and these conditions may ha\e an 
important bearing in understanding the more complex relationships 
of other species, if the conditions here simply shown are not 
exactly reproduced in vertebrates or arthropods, thev may gi\e 
some indication of the wav in which the more complex have come 
about. 
9. If the more superficial parts of the radial and oral system 
are sensory and the smaller dorsal parts motor, then it seems that 
the larger \entral strand must be a little more than sensory, as has 
been shown by numerous experiments, because of its si/e and because 
of its inter-relationships. In other words we ha\e here the origin 
of a central nervous system or associating part from a sensory por- 
tion. This mav be an important suggestion in connection with the 
origin of the central nervous system in other forms. 
RFFERENXES 
Ciicnot.L. 1887 
Etudes anatomiques et morphologiqucs sur les Ophiures. .Arch. 
Zool. Exper., Ser. 2, Vol. vi. 
Davydof,C. 1901 
Beitrage zur keniitiiis der Regenerationserscheinungen bei den 
Ophiuren. Zeit. Wiss. Zool. Bd. Ixix. 
Di'Uigc et Herotiard 190.1 
Traite de Zoologie concrete. Ill Echinodcrmes. 
Hcn,unn,,0. 188Q 
Anatomie und Histologie der Ophiuren und Crin<iiden. Jen. Zeit. 
f. Natur. Bd. xxiii. 
I.ange,Jf\ 1876 
Beitrage zur Anatomie und Histologie der Asterien und Ophiuren. 
Morph. Jahrb. Bd. ii. 
M tiller. J. 18.S4 
Ueher Aen Bau der Echinodermen. K. Akad. d. Wiss. Bd. xlv. 
(Contribution from the Zoologieal Laboratory of Pomona College) 
