Corals. 



21 



Fig. 5. 



more clearly if there is still a little colony of very small 

 sea-anemones in the schoolroom. 



Fig. 5 is a diagram to be drawn in red and white, showing the 

 upper half of the fleshy tube with the tentacles, and a cross-section 

 throngh the oaleareons 

 tnbe with its partitions. 

 To make it plainer, only 

 six long and six short 

 partitions are shown, 

 and jast as many tenta- 

 oles, each long tentacle 

 lying directly above a 

 long partition, and each 

 short tentacle^ above a 

 short one. This figure 

 not only shows the re- 

 semblance between the 

 coral animal and the 

 sea-anemone, and the re- 

 lations of the fleshy parts to the calcareous skeletou, but also the 

 manner in which the fleshy base of the tabes (6) extends from one 

 to another, thus binding together all the animals. It is this which 

 forms the spongy filling of lime (c) between the tubes, and from 

 which new tubes bud as the colony grows. A vertical section 

 throngh a large piece of Galaxea will often show that moat of the 

 polyps die at the end of each season ; but the next season those that 

 have lived spread out their fleshy bases and build a new spongy 

 layer of lime over the tops of the dead tubes below. 



The children will have suspected by this time that the 

 stomach, the mouth, and the poisoned lines on the tentar 

 cles of the coral are like those of the sea-anemone, as is 

 really the case. 



The class is now ready for the finger-coral, and the teacher may 

 happen to have a piece that resembles a hand with fingers, thus 

 suggesting its name. The children's observations follow : 



It is white and stony. It grows in branches. It has 

 little bits of cups on the branches. It has very small 

 tubes. The tube at the end of the branch is much larger 



