228 FUNCTIONS AND INSTINCTS. 



the water and the food it conveyed from the 

 common tube, and rejected it by the orifice of 

 the tubercles. 



The internal organization of the little tenants 

 of the common tube is given with considerable 

 detail by Savlgny, 1 the general opening at the 

 summit, or truncated end of the tube, has an 

 annular diaphragm, from which it appears that 

 they are arranged in circles round it, so that 

 in this respect they form rays ; in shape they 

 somewhat resemble a florence-flask, and have 

 alternately a long and short neck. The cavity 

 below the neck is filled by the gills and various 

 intestines, which it would be difficult to describe 

 intelligibly, in a popular manner. There seems 

 some analogy in these floating hives of luminous 

 animals, both as to size and motion, with the 

 sea-pens. 2 



No species of the genus appears to have been 

 met with in our seas, we may therefore conjec- 

 ture that a warmer climate is essential to them. 

 Their general functions beyond that of illumi- 

 nating the great theatre in which their Creator 

 has placed them, and probably affording food to 

 some of the inhabitants of the seas in which 

 they are found, have not yet been ascertained. 

 Neither of the orifices of these little animals is 

 furnished with tentacles, but their branchial 

 orifice is toothed, in this they appear to differ 



1 Ubi. supr. pi. xxii. xxiii. 2 See above, p. 178. 



