-51- 



# One might state the oase rather paradoxically in metaphysical terms 

 by saying that the animal* 8 soul or entelechy, or some part of it at 

 least resides in its substrate. (See Dreisch (1908) Steme (1891).) 



Therefore, if the activity of the animal caused the substrate to move in 

 one direction with reference to one part and in another direction with 

 reference to another part, as is the oase in the righting and deviation 

 reaction, we might expect that the unified impulse would be broken up in 

 certain detaitninate way*. 



Deviation reaction not interfered with by_ cutting ne rvous con- 

 nections with interradial a rea 



That the coordinated impulse is thus broken up by mechanical 

 traction in the deviation reaction, is made likely by the fact that 

 the reaction is perfectly normal even after the nerve net on the out- 

 aide of the epidermis was out through between the obstacle and the am- 

 bulaoral nervous system. This, of course prevented any stimulus from 

 the contact of the starfish with the obstacle reaching the tube feet, 

 but did not affect the mechanical factors in the relation of the sub- 

 strate with the tube feet. It is therefore to be concluded that these 

 mechanical factors play an important role in the deviation reaction. 



Deviation reaction not elicited by. prodding interradial area. 

 Moreover, if the nerve net between the bases of the two an- 

 terior rays be stimulated by jabbing it quickly with a knife or a blunt 

 instrument, the deviation reaction w.ill not follow* The aniaal will 

 either continue undisturbed, stop and then continue or go into the at- 

 tached condition and remain so more or less permanently. The first 

 response is by far the most common if the specimen is normally active 

 and not stimulated too harshly. I have never observed a marked change of 

 direction as is seen in the deviation reaction to say noihing of the 



