214 ISatural History Bulletin. 



coordination to pass the offending objects away from the test. 

 In order to show whether this action was entirely automatic 

 or partook of the element of choice, the following experiment 

 was tried. An animal was placed with the actinal pole 

 against the side of a large glass vessel, to which the ambu- 

 lacral feet soon adhered. In this position a portion of the 

 equator was uppermost. The balls treated with acid were 

 then placed as exactly as possible upon the equator. They 

 were promptly rolled off in the direction opposite the normal 

 one, that is, toward the apical system. This seemed a clear 

 indication that choice was exercised in deciding the direction 

 of removal. If the action of the spines and pedicellanai had 

 been purelv automatic, they would have removed the objects 

 in the* customary direction. This would have brought the 

 irritating substance in contact with the numerous sensitive am- 

 bulacral feet, which were adhering to the glass on the actinal 

 side. The conclusion that volition was involved was further 

 strengthened by placing non-irritating balls in the same position, 

 when thev were worked off in both directions indifferently. 



Another experiment was tried tc determine whether there 

 was any rudiment of memory to be discovered in the sea- 

 urchins. Placing a specimen on the table, a lighted match 

 was held near the test. The lieat caused the animal to move 

 awav from the match. After it had progressed some distance, 

 another lighted match was held on the side opposite the one 

 originally irritated. The animal at first retreated directly 

 awav from the second match, but upon approaching the place 

 where it had been burned b\" the tirst match, it turned and took 

 a course at rio-ht ang^Ies to a line drazin betzvcen the tzi'o sources 

 of danger ! The lirst match was no longer burning, of course, 

 and we ma}' reasonably surmise that the animal changed its 

 course upon remembering its former experience. The other 

 experiments were substantiallv the same as those tried bv 

 Romanes.^ 



1 "Jelly-Fish, Star-Fi^h and Sea-Urchins,"' page 301 et seq. The student 

 will be well repaid should he find time for the perusal of this entire work 

 one of the most suggestive of the many contributions to science made by 

 Professor Romanes. 



