NERVOUS SYSTEM OP ANTEDON ROSACEUS. 535 



flexed spirally into a coil. After a short time the animal came 

 to rest in a perfectly normal position, but for the spiral coiling 

 of the distal part of the injured arm, which persisted. After a 

 quarter of an hour's rest one of the uninjured arms was irri- 

 tated, causing at once active movements of the uninjured arms 

 and of the proximal part of the injured arm, but none whatever 

 of its distal part. 



Experiment 18. — In a fresh Antedon two injuries, similar 

 to that in Experiment IT, were made in one of the arms at 

 spots about an inch and a half apart. Stimulation of the arm 

 itself, or of the pinnules, between the two wounds caused move- 

 ments of the middle portion of the arm, but none whatever of 

 the proximal or distal portions. 



The two preceding experiments show that division of the 

 axial cord destroys the motor communication between the parts 

 on either side of the section as completely as we have already 

 found it to destroy the afferent or sensory communication. 

 When combined with Experiment 16, which shows that the 

 motor communication is not effected by any of the other soft 

 parts, the inference is irresistible that the sole motor communi- 

 cation is that afforded by the axial cords. One additional 

 experiment may be mentioned in support of this conclusion. 



Experiment 19. — One of the arms of a vigorous specimen 

 was amputated by a snip of the scissors. The detached arm 

 exhibited extremely active movements for about a quarter of an 

 hour, coiling and uncoiling with great force and rapidity. 

 After a time it became quiescent. It was then held in the 

 tank with the proximal end just out of water. The end was 

 carefully dried and the exposed section of the axial cord touched 

 with a needle and with a fine brush charged Avith nitric acid. 

 The slightest irritation, whether mechanical or chemical, caused 

 violent and repeated flexion of the arm. Stimulation applied 

 to other parts of the cut end produced but very little effect. 



It still remains to inquire into the functions of the commissural 



