Xo. 558] CLONAL VARIATION IN PECTIN ATELLA 



367 



ber of hooks on statoblasts from different masses in 

 order to see if there was less variation inside of one mass 

 than between different masses. This method has its 

 clear limitations ; for one does not know whether a given 

 mass is simple or compound in origin. If, in any large 

 mass, the modes, or the average, of the number of hooks 

 varies greatly between colonies, that is evidence of the 

 compound nature of the mass. If, on the contrary, the 

 averages of all the different colonies of a mass are 

 closely alike that indicates the homogeneity and prob- 

 ably simple nature of the mass — its origin from one 

 statoblast. 



TABLE III 



