166 University of California Publications in Zoology. [Vol. 4 



the turning very awkward. Nevertheless, at the end of the 12 

 lessons the starfish had gotten into the way of turning on these 

 two rays. It was now given eight free tests ; it turned every time 

 on a and b, the turning being in each case awkward. 



Thus the starfish F readily modified its behavior for a short 

 period, forming what we might call a temporary habit. But 

 owing evidently to the tendency of b to place itself wrongly, it 

 was not possible to get the animal to form a lasting habit. After 

 a period of 24 hours, it might first attach itself by a and b, but 

 finding its position awkward, it attached other rays, released 

 a or 6 or both, and turned on the other rays. Thei'eafter these 

 other rays were given the preference. 



I devoted much time to trying to train b to twist correctly, 

 by turning it forcibly, by releasing it when wrongly placed and 

 placing it in a new position, etc. But the chief effect of this was 

 to cause, as might perhaps be expected, an apparent reluctance 

 to use the ray b at all ; the partial habit already formed was 

 broken up by thus hectoring the ray b after it had attached 

 itself. 



Thus at the end of one week's training, the starfish showed, 

 after the lapse of 24 hours, very little effect of the practice. 

 However, a certain effect appeared, in that the ray b was now 

 used almost as frequently as any other — four times out of ten — 

 though at the beginning it had not been used at all. 



After another week of training, there was no further im- 

 provement, the rays a and b being merely used with average 

 frequency. 



In starfish F, therefore, a temporary habit was readily 

 formed, but a strongly marked lasting habit did not appear 

 under the conditions of experimentation. 



Starfish G. Ten preliminary free reactions showed that the 

 starfish used the ray e, 8 times ; a, 4 times ; b, 3 times ; d, 3 times ; 

 c, 2 times. The training was then directed toward getting the 

 starfish to use the ray c in a greater proportion of the reactions. 

 — any combination of other rays with c being permitted. 



After 11 lessons, in which the starfish was compelled to use 

 c in various combinations with other rays, the animal was allowed 

 (without an interval of waiting) to right itself 8 times without 



