196 



C. M. CHILD AND L. H. HYMAN. 



in H. oligactis and H. vulgaris and doutbless occur also in H. 

 viridissima. Observations on the contraction of animals bear- 

 ing buds in the earlier stages .show very clearly that when marked 

 contraction of the parent stalk or body or both occurs, some slight 

 contraction of the bud may follow and in such cases progresses 

 acropetally in the bud. In view of these facts, we believe that 



'.'-" 



, 



4J 



.;::. 



28 



FIGS. 25-31. 



such reversals of bud gradients are to be interpreted as the ex- 

 pression of physiological relations which can be directly observed 

 in the normal animals. 



The results in all agents show that the primary gradient in the 

 bud is basipetal, but that, even in the earlier stages, it may be 

 modified or reversed by contractile activity in adjoining regions 

 of the parent animal and in later stages by its own contractile 

 activity. In the higher concentrations of anesthetics and in the 

 irritant dyes certain other modifications of the susceptibility 



