ul ON ANIMAL LIFE~ 107 
duse in all stages of development (Fig. 3), some 
still in the condition of minute buds, in which 
no trace of the definite Medusa-form can yet 
Fig. 2. — Bougainvillea fruticosa; natural size. (After Allman.) 
be detected ; others, in which the outlines of 
the Medusa can be distinctly traced within 
the transparent ectotheque (external layer) ; 
others, again, just casting off this thin outer 
pellicle, and others completely freed from it, 
struggling with convulsive efforts to break 
loose from the colony, and finally launched 
