5 



ON THE ORIGIN AND 



[CHAP. 



Medusae in all stages of development (Fig. 35), some 

 still in the condition of minute buds, in which no 



FIG. 3J. Portion of colony of Bougainvillea fruticosa, more magnified. 



trace of the definite Medusa-form can yet be detected ; 

 others, in which the outlines of the Medusa can be 

 distinctly traced within the transparent ectothtque (ex- 

 ternal layer) ; others, again, just casting off this thin 

 outer pellicle, and others completely freed from it, 



