FACTS AlJori" \Vi:i.I. KNOWN ANIMALS. 



SO 



of tlie woiuUirul tiaii>rorinatious wliidi this llnirJtloUwia \n\- 

 dergocs should lonsuU the niagnilicont works of Alexander 

 Agassi/, on the subjert. 1 have only time to state that the 

 star-fish i)n)i)er develops on the ah-oral end of the larva, 

 whieh it linally absorbs, and that the adult star-Hsh, with 

 its long arms, is not developed for two or more years, the 

 form meanwhile remaining eonieal or disc-shaped. 



Fig. 4. — Diagramatic view of young Starfish : A, /»', C, Bipinnaria stage in 

 different ages; D, Braciiioiaria stage. (The black lines represent ciliated bands; 

 the shading the space between the pnv-oral and post-oral bands ; w, the mouth; 

 an the anus. (After Miiller. ) 



The star-fish swallows the younger oysters shell and all. 

 and after the soft parts are absorbed the shell is cast out of 

 the stomach by eversion : but older oysters are not so easily 

 managed. To tackle one the. star-fish grasps it in his five 

 arms and then little by little breaks ofl' the margin of the 

 shell 1>y the muscles at the entrance of his stomach, and 

 when a sufHcient opening has been efiected the distensile 

 mouth is intruded until tin- «;oft oyster is seized and T-on- 

 sumcd. 



Thestar-fishmust live to an old age, as, according to Agassiz, 

 .some 14 years are required for full growth and development. 

 Its ability to reproduce lost members is well known. Certain 

 species like the Ophiurans, or brittle-stars, have, in fact, a 

 faculty for dismemberment which is truly marvelous, for 

 they break their limbs to pieces when irritated. The rays, 

 when broken, are renewed, but the stomach, if severed, or 



