28 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



and to the muscles and organs in the body walls. In addition 

 to these main nerves is a complex network of fibers supplying 

 the alimentary canal and other internal organs. Everywhere 

 over the surface of the body is a network of minute fibers con- 

 nected with the sense organs, pedicellarise, and branchiae of the 

 integument. 



The whole nervous system controls the coordinated actions 

 of 11 parts of the body only when the connection with the nerve 

 ring is intact. If the radial nerve at the base of one or more 

 of the arms is cut, each arm so isolated from the nerve ring will 

 act independently of all the others, and no coordinated move- 

 ments of the body are possible. The nerve ring may therefore 

 be looked upon as the coordinating center of the nervous system 

 of this animal. 



Reproductive System. The sexes are separate, with paired 

 sexual glands extending into each arm. These glands develop 

 in close connection with the madreporic canal in a mass of 

 tissue known as the axial organ. The development of the sexual 

 products is described in detail in the chapter on reproduction. 



HABITS 



Many interesting papers have been published in recent years 

 describing in great detail the habits of various species of star- 

 fish and their responses to stimuli. In addition to the classical 

 works of Romanes* and Preyer,f the papers of Cole, Cowles,^ 

 Jennings,** von Uexkullff and others discuss the behavior of 

 these animals when subjected to a great variety of conditions. 



* In addition to several more technical papers, the book entitled, " Jellyfish, 

 Starfish, and Sea-urchins," published in the International Scientific Series, 1885, 

 contains a most interesting popular account of the natural history of the starfish. 



t Ueber die Bewegungen der Seesterne. Mitteilungen aus der Zool. Station zu 

 Neapel, Band 7, 1887. 



Cole, L. J., Direction of Locomotion of the Starfish (Asterias forbesii). Pub- 

 lished in Science, vol. xxxi, 1910. This paper consists of a brief statistical study 

 of the direction of movement of our common starfish in the absence of directive 

 stimuli. 



If Cowles, R. P., Reaction to Light and other Points in the Behavior of the Starfish. 

 In Publication No. 132, Carnegie Institution, Washington, 1909. Describes the 

 reactions of two species of starfish when subjected to various kinds of light. 



** Jennings, H. S., Behavior of the Starfish Asterias forreri de Loriol. In the 

 University of California Publications in Zoology, vol. iv, 1907. Observations on 

 the habits of a species of Pacific Coast starfish and its reactions to various kinds 

 of stimuli. 



tt In addition to several technical papers by von Uexkiill, a popular account of 

 the general behavior of the starfish is contained in his recent book entitled, " Umwelt 

 und Innenwelt der Tiere." 



