244 THE OCEAN WORLD. 



carries from space to space certain groups very exactly circumscribed 

 and individualised. Each of these groups consists of a nursing polyp, 

 having its fishing-line with a special floating air -bladder, a repro- 

 ductive hud male or female, and a protecting casque enveloping the 

 whole. 



Another species having a great resemblance to the Praya is 

 Groleolaria aurantiaca (Plate VIII.), or orange Galeolaria, which is 

 represented on the opposite page, borrowed from the fine " Memoir of 

 the Inferior Animals of the Mediterranean," by Carl Yogi Here 

 we find only two great floating bladders placed at each extremity of 

 a common trunk, and serving the purpose of a locomotive apparatus 

 to the whole colony. This trunk carries in like manner polyps 

 placed at regular intervals forming isolated groups, provided each with 

 its protecting plates. But there is no special swimming apparatus for 

 each of these groups. Moreover, each colony is either male or female. 



PHYSALIA, 



Let us finally note among the SiphonophoraB a zoophyte which has 

 attracted great attention, and has been described under many names. 

 Sailors call it the sea-bladder, from its resemblance to that organ ; it 

 is also known as the Portuguese man-of-war, from its fancied re- 

 semblance to a small ship as it floats along under its tiny sail. 

 Naturalists after Eschscholtz call it Physalia utriculus, from the 

 Greek word <pvo-a\ls, a bubble, and ntriculus from its stinging 

 powers. It was long thought that the Physalia was an isolated 

 individual. But, according to recent researches, they form, like the 

 species already described, an animal republic. 



Let us imagine a great cylindrical bladder dilated in the middle, 

 attenuated and rounded at its two extremities, of eleven or twelve 

 inches in length, and from one to three broad. Its appearance 

 is glassy and transparent, its colour an imperfect purple, passing to 

 a violet, then to an azure above. It is surmounted by a crest, limpid 

 and pure as crystal, veined with purple and violet in decreasing tints. 

 Under the vesicle float the fleshy filaments, waving and contorted 

 into a spiral form, which sometimes descend perpendicularly like so 

 many threads of celestial blue. Sailors believe that the crest which 



