XXV111 INTRODUCTION. 



bous base of the tentacles, or from the tentacle itself, or 

 from the radiating canals. 



The free zooid, then, after its detachment, may pass 

 through many stages of growth and development itself, 

 and originate a large number of similar organisms, before 

 proceeding to discharge its principal function, the elabo- 

 ration of the generative elements. With the escape and 

 dispersion of the latter, its existence, in all probability, 

 usually terminates. 



Towards the end of its course it sometimes loses its loco- 

 motive organs and passes into a state of quiescence, and in 

 this condition closely resembles, in all essential particulars, 

 an ordinary polypite. The locomotive energy fails, the 

 umbrella is first reversed and then shrinks into a shapeless 

 mass, which hangs about the base of the body, and bears 

 the tentacles streaming behind it. (Woodcut, fig. xiii.) 



Fig. xiii. 



The medusiforin zooicl of Podocoryne carnca in its quiescent stage. a. Tlic 

 remains of the swimming-bell, b. The tentacular bulbs, o. The ova in the 

 walls of the manubriuui. 



The adaptive dress which had fitted the zooid for a free 



