-20- 



be fairly constant within the limits studied* 



In ffyonopodia the relationship is even more constant, 

 though it has a -wholly diffe^nt value as seen from tha following 

 table: : 



Strength of pull Release at 3/53 



(2 in fig.) (3 in fig.) 



Here the average quotient is 2. 06. The tube foot is 2,06 times at 

 strong to hold as it is to pull. 



The difference in tha valu of vlie figure ia due to spec- 

 ific differences between the two starfish. It is not in any way 

 correlated with ability of the tube feet to attach when not in th 

 locomotor state. An attached stationary Asterina is very easily re- 

 moved from the substrate and only once have I seen a tube foot torn 

 off in the process. On the other hand Pyono podia the attachment 

 of whose tube feet during the st*p reflex is much less than that of 

 Aaterina. would when in the stationary clinging state hold with such 

 tenacity to the substrate, that it was only with much patience and 

 the loss of many of the animals tuba feet that I could pull it loose. 

 When the starfish was once released from the substrate, if the ten- 

 dency to attach continued, as it often did, I was confronted with 

 the equally difficult and much more unpleasant task of releasing the 

 animal from my own hands. I have spent the best part of an hour dis- 

 entangling the twenty-two arms of an eighteen inch Pyppnop o iia_ from 

 myself and the side of the aquarium* 



