i62 TOILERS IN THE SEA. 



end united to a number of radiating tubes, which 

 arch over, and pass downwards, to the edge of the 

 swimming-bell, where they unite to a hollow circular 

 ring, or canal. At the margin of the swimming-bell, 

 and near the base of the tentacles, is one or more eye- 

 spots, probably having the functions of an eye in 

 higher organisms. The hollow cavity of the tube is 

 the stomach, from which the digested food passes 

 into the radiating canals, through which it circulates. 

 The mouth is sometimes lobed, and sometimes 

 fringed with a few short tentacles, to assist in the 

 acquisition of food. This is a brief summary of the 

 appearance, and structure, of the Medusa-like free 

 zooid, in so far as relates to its movements, and 

 method of living. All that concerns its other func- 

 tion, the perpetuation of the species, will be detailed 

 further on. 



" It would be difficult," writes Mr. Hincks, " to 

 exaggerate in speaking of the beauty of these floating 

 flower-buds, as they may well be called. The vivid 

 tints which they often display, the gracefulness of 

 their form, the exquisite delicacy of their tissues, and 

 the vivacity of their movements, combine to render 

 them singularly attractive. Frequently they are so 

 perfectly translucent that their bubble-like forms only 

 become visible in a strong light. In other cases the 

 umbrella is delicately tinted, while the central tube 

 (manubrium) displays the gayest colouring, and 



