NATURE STUDY IN SCHOOLS. 4ft 



comes paralyzed* The lasso draws it to the tentacle, which throws it into 

 the mouth, from which it passes through a short gullet to the stomach. 



Water passes in through the tips of the tentacles, carrying air with it, 

 into a partition between the stomach and the next partition, which is divid- 

 ed into a great many cells. Each of these cells has a window on each side. 

 As the water passes through these cells, it bathes them. It is discharged 

 through the mouth*, as are all substances which cannot be digested. 



Sea water must consist of everything from which land is made up of, be- 

 cause the rivers flow through all kinds of soil, and carry a certain amount of 

 it with them to the sea. Among the things thus collected is carbonate of 

 lime, of which coral is made. The polyps collect this from the water and se- 

 crete it. 



A great many years ago, a great glacier extended all over New Eng- 

 land, and as far west as Cincinnati, Ohio. This glacier was about six thous- 

 and feet deep, as it did not quite cover Mt. Washington. 



In the summer, when the glacier began to thaw, it naturally flowed to 

 the place where the land was the lowest, the basin of the Mississippi. At 

 this time the great river was about ten times as wide as it was formerly. 



At any time the Mississippi carries a great amount of sediment with it 

 to its mouth, but at this period it must have been very much greater. 



When this sediment reached tlie Gulf of Mexico, it collected there at 

 first, but the Gulf Stream soon began to wash this eastward until it collect- 

 ed at last where the Bahamas now are. The polyp will not live in water, 

 deeper than one hundred and fifty feet. 



The polyps grow in the form of a circle or ring, flat on top first. The 

 mud kills the polyps, and as it kind of hollows in the middle, the mud col- 

 lects there and the island reaches the water in the shape of a ring, the in- 

 ner part of which is called a lagoon, and affords a safe harbor. The lagoon 

 always has an opening. 



The next thing to consider is the vegetation of the island. The first 

 form which appears is the mangrove. In March a flower appears and soon 

 forms into a fruit. The fruit takes over a year to mature. In May or June 

 it drops off, when the sea is calm and floats to some land, where it takes 

 root and grows. Next comes the cocoanut, and perhaps the birds drop some 

 seeds. Some of these islands are inhabited. A striking instance of this kind 

 of island is Whitsunday Island in the Pacific Ocean 



Coral, by Margaret L. Kingsbury. 



The coral is the bony frame of the coral polyp, and may be properly 

 called the skeleton of the polyp. 



