THE PORTUGUESE MAN-OF-WAK. 



355 



shade of purple and azure, rises a vertical comb, the upper 

 border of which sparkles with fiery red. This beautiful float 

 has a small openiDg at either 

 end, and strong muscular 

 walls, so that by their con- 

 traction its cavity can be con- 

 siderably diminished. And 

 thus partly by the escape of 

 air forced out through the 

 openings, and partly by the 

 compression of what remains, 

 the specific gravity is so much 

 altered as to admit of the 

 animal's sinking into the 

 deep when danger threatens. 

 Numerous polyps proceed 

 from the lower surface, ac- 

 companied by tentacles hav- 

 ing a sac-like extension at 

 their base, and hanging down 

 in beautifully blue and violet 

 coloured locks or streamers. 

 When fully extended, these 

 tentacles form fishing lines 



fifteen Or sixteen feet long, Physalia caravella.— (Considerably reduced.) 



which, as their thread-cells 



, Pneumatophore, or float-bladder. 

 Tentacles. 



Folypites. 



are uncommonly large, at 



once paralyse the resistance of the fish or cephalopod they meet 

 with. Then rolling together, they convey the senseless prey to 

 the numerous mouths of the compound animal, which, sucking 

 like leeches, pump out its nutritious juices. In this manner the 

 greedy physalia devours many a bonito or flying-fish of a size 

 far superior to its own, and such is the corrosive power of 

 its tentacles that even man is punished with excruciating 

 pains when heedlessly or ignorantly he comes within their reach. 

 " One day," says Dutertre in his " History of the Antilles," " as 

 I was sailing in a small boat, I saw a physalia, and as I was 

 anxious to examine it more closely, I tried to get hold of it. 

 But scarcely had I stretched out my hand when it was suddenly 

 enveloped by a net of tentacles, and after the first impression of 



