178 Z. ASTEROIDA. Pennatula. 



regular and synchronous pulsations of the minute fringed arms of the 

 whole polypi." And Bohadsch asserts that he has been a witness of 

 this spectacle. " Deget nostrum Zoophyton in altiori mari, ubi in- 

 terdum cum aliis piscibus capitur. Dum versus maris supei'ficiem 

 fertur, buUulae innumerae corpus ejus circumdant, quae stellarum instar 

 de die splendent ; id quidem non hac occasione, sed anno 1749, dum 

 Liburno Marsiliam versus per mare proficiscerer, observavi. Quo 

 tempore in historia naturali minime versatus corpus bullulis nitens ad 

 quatuor circiter pedes infra superficiem maris conspiciens e nautis 

 quaesivi, quidnam rei esset ? qui Pennam esse pro responso dedere." 

 An. Mar. p. 107 — Linnaeus had thei'efore some grounds for inserting 

 the " phosphox'escent Sea- Pens, which cover the bottom of the ocean, 

 and there cast so strong a light, that it is easy to count the fishes and 

 worms of various kinds sporting among them" — amongst the most 

 memorable productions in Nature, See Smith's Tracts relating to 

 Nat. History, p. 43. But some authors, as Lamarck and Schweigger, 

 reasoning from what is known regarding other compound animals, 

 have denied the existence of this great locomotive power in a zoo- 

 phyte placed so low in the scale, as contrary to every analogy, and 

 not necessary to the existence or wants of the animal. And there 

 is little doubt these naturalists are right, for, when placed in a basin 

 or plate of sea-water, the Fennatulae are never observed to change 

 their position, but they remain on the same spot, and lie with the 

 same side up or down just as they have been put in. They inflate 

 the body until it becomes in a considerable degree transparent, and 

 only streaked with interrupted lines of red ; they distend it more at 

 one place and contract it at another ; they spread out the pinnae, and 

 the polypes expand their tentacula, but still they never attempt to 

 swim or perform any effort towards locomotion. Our fishermen 

 believe that they are fixed at the bottom with their ends immersed in 

 the mud, and the paleness of the base, when viewed in connection 

 with the preceding observations, go far, in my opinion, to prove this 

 statement to be correct. " Si les pennatules nagent aussi," says 

 Blainville, " ce dont je doute un peu, quoiqu'elles rampent tres-lente- 

 ment, c'est peut-etre en chassant le fluide qui est entre dans leur 

 systeme acquifere, plutot qu'a I'aide des pinnules polypiferes." — Ac- 

 tinolog. p. 83. 



As the name imports, this Pennatula is a phosphorescent animal, 

 but the light, of a faint blue colour, is emitted only under circum- 

 stances that tend to shew that the polypes have felt some painful ir. 

 ritation which they would drive away by the dread influence of their 

 tiny lamps. I have repeatedly kept living specimens for several days 



