22 Lessons in Zoology. 



than the others. The large tabe has partitions on the 

 inside and on the outside too, but the little tubes are only 

 rough. I think that is because the tubes are so small that 

 the partitions can't grow very far. The smallest tubes of 

 all are close to the large tube at the end of the branch. 

 They look as if they had budded from the large tube. 



Some of these obserrations mnst be drawn ont bj snch qnestiona 

 aa will readily oocur to any teacher. 



Now if a branch of the coral is broken and passed 

 around the class for the scholars to examine the broken 

 '•uds, while one with an eye for beauty, may see 

 " something like lace with a star in the middle," and 

 another only " a pieoe of stone with a little wheel in 

 it " ; some one will finally discover that " the middle 

 of the branch looks like a cross section of a tube " 

 (Fig. 2a). In this way children can find out for them- 

 selves that the large tube at the end of a branch, which 

 has kept on growing year after year, is the one from 

 which all the rest have budded. Great bushes of this 

 coral sometimes grow to the height of sixteen feet, so we 

 kdow that the parent polyp of each branch must live 

 tu a great age. 



The stony corals are the reef-bnildera, and a large part of every 

 coral reef consists of branches of madrepore beaten and ponnded 

 by the wavea into a mass of coral rook. Theae lessons on stony 

 corals may well be followed by an imaginary trip to the ooral 

 islands for a geography lesson. 



