NATURE STUDY IN SCHOOLS. 97 



Sometimes people go out in a small boat and take a Avater-glass, which 

 is a piece of common window glass fastened in the bottom of a box. A large 

 piece of glass is sometimes inserted in the bottom of the boat, and as tie 

 glass acts as a lens when it rests on the water, the beautiful things in the sea 

 are magnified and seem to be close at hand, instead of many feet below the 

 eye. 



The person who first discovered this beautiful coral named it gorgonia 

 probably remembering the old fairy story of mythology. The story tells of 

 three sisters, called the Gorgons, who had snakes for hair. So this structure, 

 with its long, curling branches is called gorgonia from its resemblance to the 

 Gorgon's snaky locks. 



Gorgonias grow so fast to the rocks or shells in the sea that they can- 

 not be pulled up by the hand without either breaking the gorgonia or over- 

 throwing the person. So naturalists who gather them, take a hammer with 

 which to strike at the base and break off the piece of rock to which it is 

 clinging. 



• The most beautiful gorgonia is the sea- feather, which reminds one of an 

 ostrich plume. This grows in swiftly-flowing currents of the sea, as it bends 

 easily and will not break. 



The rock gorgonia is about the color of the coral island to which it clings. 

 This species often spreads over large portions of ground. 



Another is the Briareum which is without the horny axle, and so grows 

 in calm water, for the carbonate of lime of which it is wholly composed, 

 being pure lime, is very brittle. It is named Briareum from the hundred - 

 armed giant, Briareus, because the polyp of this species has many arms. 



All other gorgonias may be classed as those having the horny axle, ihe 

 most familiar being the sea-fan. This species grows in surf where the water 

 is rough. As nature provides protection for all things, so she has joined to- 

 gether these little arms that they may withstand the surf the better, just as 

 children when they go in bathing, join their hands and fear to separate them 

 lest the tide, should bear them away. 



All gorgonias, except Briareum, are composed of two kinds of lime, 

 phosphate and carbonate. The inner part, or axle, is composed of phosphate 

 of lime, and therefore bends easily. The outer covering is carbonate of lime, 

 and is easily crumbled in the fingers. 



The wave of agitation in the ocean averages about forty feet, but in a 

 hurricane the agitation is much deeper. During storms, the gorgonias are torn 

 up by the waves and are washed onto the shores of the coral islands, where 

 they form long windrows, sometimes two feet high and six or eight feet 

 wide. 



When the rain falls it dissolves the outer covering of carbonate of lime, 

 and so the horny axle of phosphate of lime is left bare. It is the carbonate 



