Nov. 16, 1»83.] 



KNOWLEDGE ♦ 



305 



which we were running seemed to meet the horizon in two 

 sharply defined points like the ends o£ two slightly slanted 

 rods. Lowering the body the ends drew apart. Raising 

 it they approached again ; and alternately raising and 

 lowering the body, keeping the eyes steadily fixed on the 

 horizon, the ends seemed to approach and draw apart as if 

 really moved to and fro. 



Of course, this was not in itself a proof of the earth's 

 rotundity, only an illustration. For, a believer in a flat 

 earth might argue that the surface of the prairie was 

 really rounded, and could no more prove the earth rotund 

 than a round hill could. But the illustration becomes a 

 proof for those who know the enormous range of the 

 prairies in Western America, and that if the earth were 

 flat, and the phenomenon we are considering had to be 

 explained by a rotund prairie, the rotundity would have to 



SEA ANEMONES 



AT THE FISHERIES EXHIBITION. 



By Thomas Kimber. 



VIII. — THE DAHLIA. 



Actinia crassicornis (Miiller). Actinia coriacea (Cuvier). 



THIS large, handsome anemone is found abundantly 

 along all the British coasts. Only one other species, 

 the Strawberry, is more numerous. In colour the Dahlia 

 is very capricious ; its disk and tentacles sometimes display 

 rich purple and amber hues, at other times the most 

 delicate rose and white tints. In some instances the disc 

 is rich orange and crimson, and the tentacula are of the 

 purest white, while other varieties are met with compara- 





^ ^ 



D.ahlia Anemone the natural size. 



rise many miles above the earth's level to explain a 

 phenomenon observable over so great a range in distance. 



But these papers are not in any case intended for the 

 believers in a flat earth. These are really so few and so 

 foolish that they are not worth the trouble of convincing, 

 even if it were possible to convince by reasoning those who 

 want reasoning faculties. It would be as reasonable to 

 invite a cherub to take a chair as to ofTer arguments to the 

 earth-flattcners. Our Pretty Proofs, though most of them 

 are really proofs, have been ofTercd chiefly as illustrations 

 likely to interest tliose who know that in hundreds of ways 

 the rotundity of tlie earth, the distance of the sun, and 

 the dimensions (generally) of the solar system, have been 

 placed beyond all possibility of doubt and question. 



The End. 



tively dull in colouring. The tentacles usually are thick 

 short, obtuse, and annulated with white and red. Whert 

 however, the column is of uniform flesh or cream-colour 

 they are of the same hue and without rings. 



In the Fisheries Exhibition there were many fine 

 examples quite equal in size to our illustration. At the 

 present time are to be seen in the Brighton Aquarium, 

 many individuals and some groups not inferior in any 

 respect to the handsomest exhibited at the Fisheries. The 

 curator, Mr. Lawler, has been most successful in this 

 department, and with excessive care has succeeded in 

 maintaining for some years one of the finest exhibitions of 

 sea anemones in the United Kingdom. 



A distinctive feature of Crassicornis is the quickness 

 with wliich its body is swollen with water and assumes a 

 bladder-like and diaphanous form. In this condition the 



