1907] Jcunhigs. — Behavior of the Starfish. 167 



interference. It used the ray c seven times out of the eight. The 

 temporary habit was thus (luickly formed. Similar results were 

 reached on several different days, when the free tests were given 

 in immediate succession to the "lessons". 



After one week of training (ten lessons per day) the animal 

 was allowed to rest 24 hours, then was given ten free tests. There 

 was no evidence of the effects of training, the rays being used as 

 follows : e, 7 ; fZ, 4 ; 6, 4 ; C, 3 ; a, 2. 



During the next seven days, the starfish was given fifteen 

 lessons per day,— five lessons in the morning, five at midday, 

 five in the evening. In these lessons the plan of training was 

 made a little more definite, the starfish being compelled to wse 

 the rays b and c in each reaction. At the end of seven days there 

 was an interval of 24 hours without training. Then ten free 

 experiments gave the following results: 



6, 6; c, 6; e, 4; fZ, 3: a, 2. 



Thus the effects of the training were very marked after the 

 interval of 24 hours. 



Starfish H. This starfish was very large and stiff,— evidently 

 much older than the others. Ten preliminary experiments 

 showed a marked tendency to use the combination a -\- e (five 

 times) while b -{- c was, as usual, rarely used (once). The train- 

 ing was directed toward getting the animal to use b + c. The 

 method of training differed from that used in other cases. The 

 .starfish was placed on its back in a tilted position, and so held 

 for a time, that only the rays b and c were in contact with the 

 bottom. These rays then attached themselves. The starfish was 

 now allowed to sink flat on its back. Other rays now attempted 

 to take hold, but this was prevented. 



Training was in this case quite unsuccessful. It appeared to 

 be extremely difficult for this starfish to turn on the rays b and c. 

 The ray b was invariably twisted in the wrong direction, so that 

 even if b and e were first attached, the animal later took hold and 

 turned with other rays, if possible. It practically never turned 

 on the rays b and c, save under duress, and even then only after 

 an obstinate struggle, and in a most awkward way. A week's 

 training, ten lessons a day, had no effect in changing the reaction 

 to b and c. 



