412 THE AQUARIAN NATURALIST. 



In order to examine them satisfactorily, it is abso- 

 lutely necessary that a clear reflected light should be 

 transmitted through the object, care being taken to 

 avoid all artificial illumination, the latter being totally 

 inadequate to supply that delicate and perfect defini- 

 tion requisite for the exhibition of creatures so ex- 

 ceedingly minute and evanescent : 



" Transparent forms too fine for mortal sight, 

 Their fluid bodies half dissolved in light." 



All things being thus arranged, there is no diffi- 

 culty whatever in watching the many wonders con- 

 nected with a spectacle so miraculous as that afforded 

 by the inhabitants of the hitherto invisible colony, as 

 each individual seems to start into existence, and 

 disport itself with an energy and activity little to be 

 expected in creatures apparently so uncared for and 

 neglected. 



In the more transparent species, even while the 

 little animal remains quiescent in its crystal residence, 

 it may be observed through the hyaline walls of its 

 retreat contracted and doubled on itself, the tentacula 

 compressed together, and the orifice of its habitation 

 closed by a kind of membranous lid (PI. VII. fig. 7), 

 \vhich, as the polyp rises to display its parts, unfolds 

 like the inverted finger of a glove. 



A circlet of setae, or microscopic bristles of in- 

 describable slenderness, next makes its appearance, 

 rising out of the apex of the cell, and followed by the 

 flexible portion on which it is set. The tentacula 

 next pass up between the setae, and push them asunder; 

 while the integument of the animal is seen gradually 



