III.] 



METAMORPHOSES OF INSECTS. 



struggling with convulsive efforts to break loose 

 from the colony, and finally launched forth in the 

 full enjoyment of their freedom into the surround- 

 ing water. I know of no form in which so many 

 of the characteristic features of a typical hydroid 

 are more finely expressed than in this beautiful 

 species." 



Fig. 36 represents the Medusa form of this species, 



FIG. 36. The Medusa form of the same species. 



and the development thus described may be re- 

 garded as typical of the Hydroida ; yet, as already 

 mentioned, the ^Eginidae do not present us with 

 any stage corresponding to the fixed condition of 

 Bougainvillea, but, on the contrary, are developed 

 into Medusae direct from the egg. 



On the other hand, there are groups in which 



E 2 



