1907] Jennings. — Behavior of the Starfish. 143 



Starfish A. — Twenty experiments. Rays used: e, 17 times; 

 «, 15; C, 4; d, 3; b, 1. 



Combinations of adjacent rays used : a-\- e, 12 times \ c -\- d, 

 2; a + 6, 1; cZ+e, 1. 



Ten experiments three days later. Rays used : e, 8 ; d, 8 ; a, 3 ; 

 h, 1; c, 1. 



Combinations of adjacent rays : d -\- e, Q; a -\- e,2; a -[-h, 1\ 

 c-\-d,l. 



Totals of the thirty experiments : Rays used : e, 25 ; a, 18 ; 

 c7, 11; c, 5; h, 2. 



Combinations used : a-\- e, 14 ; d -\- e, 7 ; c -{- d, 3 ; a -\-b, 1 ; 

 b + c, 0. 



There is thus in the starfish A a strong tendency to use the 

 ray e, this being employed twenty-five times out of a possible 

 thirty. The ray b, on the other hand, is discriminated against; 

 it attached and pulled only twice out of the possible 30. Of the 

 pairs of adjacent rays, a -|- e is used in nearly half of all cases, 

 while 6 -(- c is never used. 



Starfish B. — Fifteen experiments. Rays used: a, 15; e, 14; 

 b, 1 ; d, 5 times as a third subordinate ray in connection with 

 a -\- e; c, 0. 



Combinations of adjacent rays : a -\- e, H; a -\- b, 1. The rays 

 a -|- e were accompanied in five cases by d, which attached itself, 

 but was mainly passive. 



Ten additional experiments three days later. Rays used : 



a, 7; e, 4; &, 3; c, 3; (Z, 2. 



Combinations of adjacent rays : a -\- b, 2; a -{- e, 1. The other 

 reactions were performed with two non-adjacent rays in action, 

 — a ray between them being passive. 



Total of the twenty-five experiments : Rays used : a, 22 ; e, 

 18; d, 7; 6,4; c, 3. 



Combinations of adjacent rays : a -{- e, 15 ; a -{- b, 3 ; b -\- c, ; 

 c-{-d,0;d-\-e,0. 



Here again we see a strong tendency to use the rays a and e 

 in preference to others. 



Starfish C. — Ten experiments. Rays used : £>, 5 ; cZ, 4 ; a, 3 ; 



b, S; c, 1. 



Combinations used : a -\- b,3; d -\- e, 2. The rays d and e were 

 each employed quite alone in two reactions. 



