PLUSTRA. 357 



cylinder protrudes, and then the integument of the body, 

 unfolding like the inverted finger of a glove, displays the 

 exterior of the animal, crowned by about thirty-five tenta- 

 cula in campanulate arrangement. The form of the polype 

 is elegant, light, and beautiful. It rises very leisurely from 

 the cell ; but its retreat is most precipitate, vanishing in a 

 moment; and thus is the cloud composed of multitudes 

 dissipated from before the observer." All this we have 

 lately contemplated with great delight. 



Not less interesting are the observations of the Eev. T. 

 Hincks, recorded in the ' Annals of Natural History/ re- 

 specting the gemmules excluded from the fleshy moss, 

 destined to form new polypidoms ; but I must limit myself 

 to very short extracts. The gemrnule is described as very 

 beautiful, thickly fringed with cilia round the border. " Its 

 movements are irregular. Sometimes it creeps along, using 

 its cilia as feet; at other times it swims pretty rapidly 

 through the water; at others it tumbles over and over. 

 Occasionally it floats on its back with its cilia upward, and 

 in this state resembles a miniature boat. After a short 

 time the cilia suddenly cease to play, the creature becomes 

 attached, and is gradually developed into the cell and 

 polype which are to be the nucleus of an extensive colony." 



