508 



CCELENTERA TES. 



buds. Each bud is a living, feeding, coral-animal, surrounded by its crown of 

 tentacles. These madrepores play no small part in building up coral-reefs, and 

 the many different elegant forms which they assume (while keeping to their 

 method of budding) is astounding. Some corals, again, do not form true branches, 

 but may cover the ground like a field of corn, a good example of this type being 

 found in Cladocora coespitosa, which inhabits the Mediterranean and Adriatic seas. 

 Here the single individuals form somewhat long tubes, and the buds arise 

 laterally at the lower end, then bend upward and grow alongside of the parent, 

 without any further connection or fusion. The spaces between the different 

 rising polyps are not filled in with secreted hard matter, but the latter grow up 

 side by side free. The stock, therefore, is easily broken. This coral flourishes 

 extraordinarily in many places, covering areas of over one hundred square yards, 

 with a growth of a foot in height. 



The method of growth just described is shown also by another and quite 

 different coral, Astroides calycularis. As in Cladocora, just described, the single 



A MASSIVE CORAL, Astroides (nat. size). 



polyps, with their calcareous tubes or pedestals, are not fused together by any 

 cementing substance. The yellowish red polyps are seen standing out a great 

 height above their cavities, much more so than is usual in corals. The larvae of 

 these corals leave the egg while still in the large, chambered body-cavity of the 

 parent, where they swim about for a time, till they escape through the mouth. 

 They are long and worm-like, and slightly thicker at the posterior end, but may 

 change considerably in shape. They swim about rapidly by means of their 

 covering of cilia, the thicker end being foremost. The mouth appears at the thinner 

 end soon after the larva leaves the body of the parent. Its free-swimming life has 

 been known to last as long as two months; but under natural conditions it would 

 probably be shorter. A strong sirocco had a marked effect upon the larvae, which 



