COKALS. 387 



Still, although the general fact is known, its details are not so 

 familiar. 



In the active season of Coral life, that is, from May to Aiigust 

 or September, millions of young Corals are launched into the 

 world. When they first pass into the sea from the mouth of their 

 parent, they are tiny flask-shaped beings, covered with minute 

 cilia, by means of which they can pass through the water with 

 some rapidity. They have a kind of mouth at the small end, 

 which, corresponds to the neck of the flask, and it is a curious 

 fact that they always swim with the large end forwards. 



After a time they change their shape, elongating until they 

 look like little white worms, but still moving ahout after the same 

 fashion. They pass some time in this phase of existence, and 

 then settle down upon some fixed object, such as a rock, and 

 adhere to it by the enlarged base. Scarcely have they done so 

 than they again alter their shape, and assume a form so different 

 that no one who was not acquainted with the little creatures 

 could recognise thenx Instead of being long and worm-like, 

 they now contract themselves in length, while they proportion- 

 ately increase in width, and look something like an echinus, or 

 sea-urchin. 



It is a curious fact, that up to this time they have passed 

 through four stages, and in each stage they change in length. 

 Before they issue from the parent, they are nearly spherical, but 

 when they pass into the sea they assume the flask-like shape. 

 They next elongate themselves considerably, and then suddenly 

 become even shorter than their width. 



In this fourth stage, the mouth is surrounded by eight little 

 cushion-like projections, which soon sprout into the beautiful 

 fringed tentacles which give to the animal so flower-like an 

 appearance. 



When it has arrived at this stage of existence, the young 

 Coral begins to develop some new and remarkable powers. From 

 various parts of the body spring little projections, which soon 

 exhibit an orifice like the mouth of the original Coral, and in a 

 short time, this aperture is surrounded with cushions, which 

 are developed into tentacles as before. As soon as it comes to 

 maturity, each of these supplementary Corals puts forth similar 

 buds, so that the increase is wonderfully rapid, even Ly " genima- 

 iiatiou," as this mode of nmltiplicatiou is called, not to mention 



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