Rate of Regeneration in Cassiopea xaiiiacliaiia. 



95 



In table 7 the weaker AlgCU solutions seem to have caused the regen- 

 eration processes to proceed at a rate well ahead of the control. In table 6, 

 however, the indicated effect is not so favorable. 



Table 7. — Rates of regeneration in strange chemical environments. 



* In normal sea-water third day. 

 t In sea-water and regenerating very rapidly. 

 $ Medusa throws out slime. 

 § Ceased to secrete the slime. 

 *• Disk inverted and new tissue torn away. 



These experiments show, on the whole, no marked indication of differ- 

 ences in the specific actions of the several ions upon the rates of regenera- 

 tion. The experiments are few, but even so they indicate the very complex 

 nature of growth and regeneration processes which are dependent upon 

 so many secondary influences and interactions that it will be found difficult 

 to determine when an element is producing a direct effect upon the regen- 

 eration rate or whether the effect is due in some indirect way to other con- 

 ditions incited by the actions of the chemical used. At any rate, there is 

 evident need for an extensive and careful study along these lines with the 

 view of analyzing, as far as possible, the relationships between regenera- 

 tion rate and definite osmotic and chemical changes. 



