202 



ACTION OF STRYCHNINE AND NICOTINE 



Severed rays, when nicotinized, show ventral flexure. Likewise the 

 excised floors of the rays in nicotine solution flex ventrally so far as 

 to form half circles. The isolated top sheaths of the rays, however, 



Fig. 1. 



Fig. 2. 



Fig. 3. 



Figs. 1, 2, and 3. Positions taken as the result of strychninization. The arms 

 are bent dorsally to such an extent that they cover up almost completely the back 

 of the animal, a condition illustrated in Figs. 1 and 2. Fig. 3 shows an inverted 

 animal unable to right itself, since all the arms bend dorsally. 



when nicotinized, bend dorsally just as if strychninized. From these 

 facts it must be concluded that ventral flexure of the ray depends 

 solely upon certain muscles in the floor of the ray, and that these are 



